SIST EN 303 348 V1.1.2:2017
(Main)Induction loop systems intended to assist the hearing impaired in the frequency range 10 Hz to 9 kHz - Harmonised Standard covering the essential requirements of article 3.2 of the Directive 2014/53/EU
Induction loop systems intended to assist the hearing impaired in the frequency range 10 Hz to 9 kHz - Harmonised Standard covering the essential requirements of article 3.2 of the Directive 2014/53/EU
The present document specifies technical characteristics and methods of measurements for audio frequency induction
loop amplifiers and receivers operating from 10 Hz to 9 kHz used in audio frequency induction loop systems (AFILS).
NOTE: The object of an AFILS is to transmit an audio signal to people with hearing difficulties. The receiver in
this case is normally a hearing aid with a built in telecoil.
These radio equipment types are capable of operating in the frequency band within the 10 Hz to 9 kHz range:
• either with an output connection(s) and dedicated loop(s) or with an internal loop(s);
• for audio frequency baseband transmission (un-modulated and without the use of a carrier).
The present document covers fixed induction loop amplifiers, mobile induction loop amplifiers and portable induction
loop amplifiers.
The present document covers the essential requirements of article 3.2 of Directive 2014/53/EU [i.1] under the
conditions identified in annex A.
Sistemi z indukcijsko zanko v frekvenčnem območju od 10 Hz do 9 kHz za pomoč slušno prizadetim - Harmonizirani standard, ki zajema bistvene zahteve člena 3.2 direktive 2014/53/EU
Ta dokument določa tehnične lastnosti in merilne metode za merjenje ojačevalnikov in sprejemnikov z avdiofrekvenčno indukcijsko zanko, ki delujejo v frekvenčnem območju od 10 Hz do 9 kHz in se uporabljajo v avdiofrekvenčnih sistemih z indukcijsko zanko (AFILS).
OPOMBA: Namen avdiofrekvenčnega sistema z indukcijsko zanko je prenos zvočnega signala slušno prizadetim. Sprejemnik je v tem primeru običajno slušni aparat z vgrajeno teletuljavo.
Te vrste radijske opreme lahko delujejo v frekvenčnih pasovih v razponu od 10 Hz do 9 kHz:
• z izhodno povezavo in namensko ali notranjo zanko;
• za avdiofrekvenčno oddajanje v osnovnem pasu (nemodulirano in brez uporabe nosilca).
Ta dokument zajema fiksne ojačevalnike z indukcijsko zanko, mobilne ojačevalnike z indukcijsko zanko in prenosne ojačevalnike z indukcijsko zanko.
Ta dokument zajema bistvene zahteve člena 3.2 direktive 2014/53/EU [i.1] pod pogoji iz dodatka A.
General Information
Buy Standard
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 303 348 V1.1.2:2017
01-september-2017
Sistemi z indukcijsko zanko v frekvenčnem območju od 10 Hz do 9 kHz za pomoč
slušno prizadetim - Harmonizirani standard, ki zajema bistvene zahteve člena 3.2
direktive 2014/53/EU
Induction loop systems intended to assist the hearing impaired in the frequency range 10
Hz to 9 kHz - Harmonised Standard covering the essential requirements of article 3.2 of
the Directive 2014/53/EU
Ta slovenski standard je istoveten z: ETSI EN 303 348 V1.1.2 (2017-07)
ICS:
11.180.15 Pripomočki za gluhe osebe in Aids for deaf and hearing
osebe z okvaro sluha impaired people
33.160.50 Pribor Accessories
SIST EN 303 348 V1.1.2:2017 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 303 348 V1.1.2:2017
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SIST EN 303 348 V1.1.2:2017
ETSI EN 303 348 V1.1.2 (2017-07)
HARMONISED EUROPEAN STANDARD
Induction loop systems
intended to assist the hearing impaired
in the frequency range 10 Hz to 9 kHz;
Harmonised Standard covering the essential requirements
of article 3.2 of Directive 2014/53/EU
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SIST EN 303 348 V1.1.2:2017
2 ETSI EN 303 348 V1.1.2 (2017-07)
Reference
DEN/ERM-TG17WG3-16
Keywords
harmonised standard, hearing aid, inductive
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16
Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88
Important notice
The present document can be downloaded from:
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The present document may be made available in electronic versions and/or in print. The content of any electronic and/or
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existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the
print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.
Users of the present document should be aware that the document may be subject to revision or change of status.
Information on the current status of this and other ETSI documents is available at
https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx
If you find errors in the present document, please send your comment to one of the following services:
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Copyright Notification
No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
and microfilm except as authorized by written permission of ETSI.
The content of the PDF version shall not be modified without the written authorization of ETSI.
The copyright and the foregoing restriction extend to reproduction in all media.
© ETSI 2017.
All rights reserved.
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TM
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GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.
ETSI
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SIST EN 303 348 V1.1.2:2017
3 ETSI EN 303 348 V1.1.2 (2017-07)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
Introduction . 6
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 7
3 Definitions, symbols and abbreviations . 8
3.1 Definitions . 8
3.2 Symbols . 10
3.3 Abbreviations . 10
4 Technical requirements specifications . 11
4.1 Environmental conditions . 11
4.1.1 Environmental profile . 11
4.2 General requirements . 11
4.2.1 Presentation of induction loop amplifier equipment for testing purposes . 11
4.2.2 Choice of model for testing . 11
4.2.3 Controls . 11
4.2.4 Amplifier shut-off facility . 12
4.2.5 Declarations by the manufacturer . 12
4.2.6 Auxiliary test equipment . 12
5 Testing for compliance with technical requirements . 12
5.1 Environmental conditions for testing . 12
5.1.1 General requirements . 12
5.1.2 Normal temperature and humidity . 12
5.1.3 Test power source . 12
5.1.3.1 General requirements . 12
5.1.3.2 External test power source . 13
5.1.3.3 Internal test power source . 13
5.1.3.3.1 General . 13
5.1.3.3.2 Mains voltage . 13
5.1.3.3.3 Valve-regulated lead-acid battery power sources . 13
5.1.3.3.4 Other power sources . 13
5.2 General conditions . 13
5.2.1 Normal test signals. 13
5.2.1.1 Signal input for testing . 14
5.2.2 Loop connections . 14
5.2.2.1 General . 14
5.2.2.2 Artificial loop . 14
5.2.3 Measuring receiver . 14
5.3 Induction loop amplifier . 15
5.3.1 General . 15
5.3.2 Induction loop amplifier definitions . 15
5.3.2.1 General . 15
5.3.2.2 Product Classes . 15
5.3.3 Audio frequency in band and out of band emission limits . 16
5.3.3.1 Definition . 16
5.3.3.2 Methods of measurement . 16
5.3.3.3 Limits . 17
5.3.4 Spurious domain emission limits . 17
5.3.4.1 Definition . 17
5.3.4.2 Methods of measurement . 17
ETSI
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SIST EN 303 348 V1.1.2:2017
4 ETSI EN 303 348 V1.1.2 (2017-07)
5.3.4.3 Limits . 17
5.4 Induction loop receiver . 18
5.4.1 General . 18
5.4.2 Headphone output . 18
5.4.3 Induction loop receiver definitions . 18
5.4.4 Methods of measurement . 18
5.4.5 Limits . 18
5.5 Interpretation of the measurement results . 19
Annex A (informative): Relationship between the present document and the essential
requirements of Directive 2014/53/EU . 20
Annex B (informative): Technical overview . 21
B.1 Induction loop amplifiers . 21
B.1.1 General . 21
B.1.2 Frequency response . 21
B.1.3 Field strength . 21
B.1.4 General performance criteria . 21
B.2 Induction loop receivers and test equipment . 21
B.2.1 General . 21
B.2.2 Sensitivity . 22
Annex C (normative): Measurement . 23
C.1 Standard test position to be used with internal loop equipment or equipment having a loop
connector . 23
Annex D (normative): The relationship between loop current and H-Field strength . 24
Annex E (informative): Artificial loop. 26
Annex F (normative): Induction loop amplifier emission levels and spectrum mask
measurements . 28
Annex G (informative): Determination and use of the measurement bandwidth . 29
Annex H (informative): Bibliography . 30
Annex I (informative): Change history . 31
History . 32
ETSI
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SIST EN 303 348 V1.1.2:2017
5 ETSI EN 303 348 V1.1.2 (2017-07)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Harmonised European Standard (EN) has been produced by ETSI Technical Committee Electromagnetic
compatibility and Radio spectrum Matters (ERM).
The present document has been prepared under the Commission's standardisation request C(2015) 5376 final [i.8] to
provide one voluntary means of conforming to the essential requirements of Directive 2014/53/EU on the harmonisation
of the laws of the Member States relating to the making available on the market of radio equipment and repealing
Directive 1999/5/EC [i.1].
Once the present document is cited in the Official Journal of the European Union under that Directive, compliance with
the normative clauses of the present document given in table A.1 confers, within the limits of the scope of the present
document, a presumption of conformity with the corresponding essential requirements of that Directive, and associated
EFTA regulations.
National transposition dates
Date of adoption of this EN: 17 July 2017
Date of latest announcement of this EN (doa): 31 October 2017
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 30 April 2018
Date of withdrawal of any conflicting National Standard (dow): 30 April 2019
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI
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SIST EN 303 348 V1.1.2:2017
6 ETSI EN 303 348 V1.1.2 (2017-07)
Introduction
Audio Frequency Induction Loop Systems (AFILS) have been on the market since the middle of the twentieth century,
with the first recognizable patents appearing circa 1938. AFILS are primarily used to facilitate improved
communication to people with impaired hearing and are an important tool in the reduction of discrimination against
disabled people.
The present document represents the performance of equipment which is currently on the market, which has not
previously been subjected to compliance to a "radio" directive.
AFILS are installed in places of worship, places of entertainment, places of education, ticket booths and service
counters, etc., as well as in domestic situations, providing huge benefits to users with impaired hearing.
AFILS provide an audio frequency magnetic field that couples with a receiving coil (Telecoil) fitted in hearing aids,
cochlear implants, loop listeners and testing devices. This magnetic field is generated in a wire loop that is fed by an
audio frequency amplifier which is capable of driving current through the "induction loop" which, in turn, is fed from
external signals such as those generated by microphones, audio-visual equipment and musical instruments.
AFILS operate below 9 kHz and have a very limited range (some few metres) and there is no known evidence of
interference with radio equipment.
The market for AFILS is relatively small compared with technologies such as RFID, and is physically separated from
most radio systems, so the opportunity for mutual interference problems is reduced compared to other users of the
spectrum in this frequency range.
The present document has been developed in response to Directive 2014/53/EU [i.1], which is the first radio standard
that has been produced for AFILS equipment and has been prepared to allow the assessment of audio frequency
induction loop amplifiers and receivers for compliance with Directive 2014/53/EU [i.1].
ETSI
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SIST EN 303 348 V1.1.2:2017
7 ETSI EN 303 348 V1.1.2 (2017-07)
1 Scope
The present document specifies technical characteristics and methods of measurements for audio frequency induction
loop amplifiers and receivers operating from 10 Hz to 9 kHz used in audio frequency induction loop systems (AFILS).
NOTE: The object of an AFILS is to transmit an audio signal to people with hearing difficulties. The receiver in
this case is normally a hearing aid with a built in telecoil.
These radio equipment types are capable of operating in the frequency band within the 10 Hz to 9 kHz range:
• either with an output connection(s) and dedicated loop(s) or with an internal loop(s);
• for audio frequency baseband transmission (un-modulated and without the use of a carrier).
The present document covers fixed induction loop amplifiers, mobile induction loop amplifiers and portable induction
loop amplifiers.
The present document covers the essential requirements of article 3.2 of Directive 2014/53/EU [i.1] under the
conditions identified in annex A.
2 References
2.1 Normative references
References are specific, identified by date of publication and/or edition number or version number. Only the cited
version applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
[1] Void.
[2] CEPT/ERC/Recommendation 74-01E (Siófok 98, Nice 99, Sesimbra 02, Hradec Kralove 05,
Cardiff 11): "Unwanted Emissions in the Spurious Domain".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] Directive 2014/53/EU of the European Parliament and of the Council of 16 April 2014 on the
harmonisation of the laws of the Member States relating to the making available on the market of
radio equipment and repealing Directive 1999/5/EC.
[i.2] CEPT/ERC/REC 70-03: "Relating to the use of Short Range Devices (SRD)".
ETSI
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SIST EN 303 348 V1.1.2:2017
8 ETSI EN 303 348 V1.1.2 (2017-07)
[i.3] CISPR 16-2-3: "Specification for radio disturbance and immunity measuring apparatus and
methods - Part 2-3: Methods of measurement of disturbances and immunity - Radiated disturbance
measurements".
[i.4] IEC 60118-4: "Electroacoustics - Hearing aids - Part 4: Induction loop systems for hearing aid
purposes - Magnetic field strength".
[i.5] IEC 62489-1 + Amd 1: "Electroacoustics - Audio-frequency induction loop systems for assisted
hearing - Part 1: Methods of measuring and specifying the performance of system components".
[i.6] IEC 61672-1: "Electroacoustics. Sound level meters. Specifications".
[i.7] IEC 60268-10: "Sound system equipment. Methods for specifying and measuring the
characteristics of peak programme level meters".
[i.8] Commission Implementing Decision C(2015) 5376 final of 4.8.2015 on a standardisation request
to the European Committee for Electrotechnical Standardisation and to the European
Telecommunications Standards Institute as regards radio equipment in support of Directive
2014/53/EU of the European Parliament and of the Council.
[i.9] ETSI TR 100 028 (all parts) (V1.4.1) (12-2001): "Electromagnetic compatibility and Radio
spectrum Matters (ERM); Uncertainties in the measurement of mobile radio equipment
characteristics".
[i.10] ETSI TR 100 028-2 (V1.4.1) (12-2001): "Electromagnetic compatibility and Radio spectrum
Matters (ERM); Uncertainties in the measurement of mobile radio equipment characteristics;
Part 2".
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in Directive 2014/53/EU [i.1] and the
following apply:
artificial loop: reduced size radiating dummy load equal to the nominal impedance of the loop specified by the
manufacturer
Audio Frequency Induction Loop System (AFILS): system including induction loop amplifier(s), microphones
and/or other signal sources, in which a magnetic field is created by the flow of audio-frequency current in a conductor
arranged in the form of a loop or coil
conducted measurements: measurements that are made using a direct connection to the equipment under test
customized loop: loop built according to manufacturers' loop design rules inside tested limits
dedicated loop: removable loop supplied and type tested with the AFILS equipment, designed as an indispensable part
of the equipment
NOTE: The loop has been designed or developed for one or more specific types of equipment. It is the
combination of dedicated loop and induction loop amplifier that is expected to be compliant with the
regulations.
hearing aid: personal amplification system, worn entirely on the listener, which is designed to enable a person with
impaired hearing to hear more easily
hearing instrument: hearing aid or cochlear implant
hearing loop system: See AFILS.
in band emissions: emissions on a frequency or frequencies which are inside the occupied bandwidth (10 Hz to 9 kHz)
ETSI
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SIST EN 303 348 V1.1.2:2017
9 ETSI EN 303 348 V1.1.2 (2017-07)
induction loop: current carrying loop or coil of an AFILS used to create the magnetic field
NOTE: This is equivalent to the term "antenna" used in other ETSI documents and is used in the present
document as it is the term commonly understood by the AFILS industry.
induction loop amplifier: audio amplifier designed to drive an induction loop
NOTE: This is equivalent to the term "transmitter" used in other ETSI documents and is used in the present
document as it is the term commonly understood by the AFILS industry.
induction loop listener: portable listening device that is designed to give an audible output in response to signals
produced by an AFILS
induction loop monitor receiver: equipment designed to verify the performance of an AFILS by audio and visual
means:
a) providing visible indication that it is powered and indicating when the strength of the magnetic field produced
by the loop falls within a specified range; and
b) providing an audio-frequency output by which the sound quality of the AFILS transmissions can be assessed
induction loop system: See AFILS.
internal loop: loop designed as a fixed part of the equipment, without the use of an external connector and as such
which cannot be disconnected from the equipment by the user
loop: See induction loop.
loop listener: See induction loop listener.
magnetic dipole moment: product of (Number of loop turns) × (loop area) × (loop current)
NOTE: Air loops only.
magnetic field strength level meter: instrument designed to measure magnetic field strength of audio frequency
magnetic fields
NOTE: Two types are in common use; a peak-programme meter (PPM) type having dynamic characteristics
similar to those of the Type II meter as specified in IEC 60268-10 [i.7], and a true rms meter type that
incorporates a true rms rectifier, and meets the relevant requirements for a Class 2 sound level meter as
specified in IEC 61672-1 [i.6]. Full functional specifications for both types of meter can be found in
IEC 60118-4 [i.4].
mobile amplifier: equipment normally installed in a vehicle
out of band emissions: emissions on a frequency or frequencies which are outside the occupied bandwidth (10 Hz to
9 kHz), but for which the levels are in transition to a frequency where the level may be reduced without affecting the
corresponding transmission of information
phased loop array: system of overlapping loops in which the currents are out of phase with each other
portable amplifier: amplifier intended to be carried or attached
radiated measurements: measurements which involve the absolute measurement of a radiated field
rated lo
...
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Induction loop systems intended to assist the hearing impaired in the frequency range 10 Hz to 9 kHz - Harmonised Standard covering the essential requirements of article 3.2 of the Directive 2014/53/EU33.020Telekomunikacije na splošnoTelecommunications in general11.180.15Aids for deaf and hearing impaired peopleICS:Ta slovenski standard je istoveten z:ETSI EN 303 348 V1.1.2 (2017-07)SIST EN 303 348 V1.1.2:2017en01-september-2017SIST EN 303 348 V1.1.2:2017SLOVENSKI
STANDARD
SIST EN 303 348 V1.1.2:2017
ETSI EN 303 348 V1.1.2 (2017-07) Induction loop systems intended to assist the hearing impaired in the frequency range 10 Hz to 9 kHz; Harmonised Standard covering the essential requirements of article 3.2 of Directive 2014/53/EU
HARMONISED EUROPEAN STANDARD SIST EN 303 348 V1.1.2:2017
ETSI ETSI EN 303 348 V1.1.2 (2017-07) 2
Reference DEN/ERM-TG17WG3-16 Keywords harmonised standard, hearing aid, inductive ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: +33 4 92 94 42 00
Fax: +33 4 93 65 47 16
Siret N° 348 623 562 00017 - NAF 742 C Association à but non lucratif enregistrée à la Sous-Préfecture de Grasse (06) N° 7803/88
Important notice The present document can be downloaded from: http://www.etsi.org/standards-search The present document may be made available in electronic versions and/or in print. The content of any electronic and/or print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat. Users of the present document should be aware that the document may be subject to revision or change of status. Information on the current status of this and other ETSI documents is available at https://portal.etsi.org/TB/ETSIDeliverableStatus.aspx If you find errors in the present document, please send your comment to one of the following services: https://portal.etsi.org/People/CommiteeSupportStaff.aspx Copyright Notification No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm except as authorized by written permission of ETSI. The content of the PDF version shall not be modified without the written authorization of ETSI. The copyright and the foregoing restriction extend to reproduction in all media.
© ETSI 2017. All rights reserved.
DECTTM, PLUGTESTSTM, UMTSTM and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM and LTE™ are Trade Marks of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. oneM2M logo is protected for the benefit of its Members GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association. SIST EN 303 348 V1.1.2:2017
ETSI ETSI EN 303 348 V1.1.2 (2017-07) 3 Contents Intellectual Property Rights . 5 Foreword . 5 Modal verbs terminology . 5 Introduction . 6 1 Scope . 7 2 References . 7 2.1 Normative references . 7 2.2 Informative references . 7 3 Definitions, symbols and abbreviations . 8 3.1 Definitions . 8 3.2 Symbols . 10 3.3 Abbreviations . 10 4 Technical requirements specifications . 11 4.1 Environmental conditions . 11 4.1.1 Environmental profile . 11 4.2 General requirements . 11 4.2.1 Presentation of induction loop amplifier equipment for testing purposes . 11 4.2.2 Choice of model for testing . 11 4.2.3 Controls . 11 4.2.4 Amplifier shut-off facility . 12 4.2.5 Declarations by the manufacturer . 12 4.2.6 Auxiliary test equipment . 12 5 Testing for compliance with technical requirements . 12 5.1 Environmental conditions for testing . 12 5.1.1 General requirements . 12 5.1.2 Normal temperature and humidity . 12 5.1.3 Test power source . 12 5.1.3.1 General requirements . 12 5.1.3.2 External test power source . 13 5.1.3.3 Internal test power source . 13 5.1.3.3.1 General . 13 5.1.3.3.2 Mains voltage . 13 5.1.3.3.3 Valve-regulated lead-acid battery power sources . 13 5.1.3.3.4 Other power sources . 13 5.2 General conditions . 13 5.2.1 Normal test signals. 13 5.2.1.1 Signal input for testing . 14 5.2.2 Loop connections . 14 5.2.2.1 General . 14 5.2.2.2 Artificial loop . 14 5.2.3 Measuring receiver . 14 5.3 Induction loop amplifier . 15 5.3.1 General . 15 5.3.2 Induction loop amplifier definitions . 15 5.3.2.1 General . 15 5.3.2.2 Product Classes . 15 5.3.3 Audio frequency in band and out of band emission limits . 16 5.3.3.1 Definition . 16 5.3.3.2 Methods of measurement . 16 5.3.3.3 Limits . 17 5.3.4 Spurious domain emission limits . 17 5.3.4.1 Definition . 17 5.3.4.2 Methods of measurement . 17 SIST EN 303 348 V1.1.2:2017
ETSI ETSI EN 303 348 V1.1.2 (2017-07) 4 5.3.4.3 Limits . 17 5.4 Induction loop receiver . 18 5.4.1 General . 18 5.4.2 Headphone output . 18 5.4.3 Induction loop receiver definitions . 18 5.4.4 Methods of measurement . 18 5.4.5 Limits . 18 5.5 Interpretation of the measurement results . 19 Annex A (informative): Relationship between the present document and the essential requirements of Directive 2014/53/EU . 20 Annex B (informative): Technical overview . 21 B.1 Induction loop amplifiers . 21 B.1.1 General . 21 B.1.2 Frequency response . 21 B.1.3 Field strength . 21 B.1.4 General performance criteria . 21 B.2 Induction loop receivers and test equipment . 21 B.2.1 General . 21 B.2.2 Sensitivity . 22 Annex C (normative): Measurement . 23 C.1 Standard test position to be used with internal loop equipment or equipment having a loop connector . 23 Annex D (normative): The relationship between loop current and H-Field strength . 24 Annex E (informative): Artificial loop. 26 Annex F (normative): Induction loop amplifier emission levels and spectrum mask measurements . 28 Annex G (informative): Determination and use of the measurement bandwidth . 29 Annex H (informative): Bibliography . 30 Annex I (informative): Change history . 31 History . 32
SIST EN 303 348 V1.1.2:2017
ETSI ETSI EN 303 348 V1.1.2 (2017-07) 5 Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (https://ipr.etsi.org/). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This Harmonised European Standard (EN) has been produced by ETSI Technical Committee Electromagnetic compatibility and Radio spectrum Matters (ERM). The present document has been prepared under the Commission's standardisation request C(2015) 5376 final [i.8] to provide one voluntary means of conforming to the essential requirements of Directive 2014/53/EU on the harmonisation of the laws of the Member States relating to the making available on the market of radio equipment and repealing Directive 1999/5/EC [i.1]. Once the present document is cited in the Official Journal of the European Union under that Directive, compliance with the normative clauses of the present document given in table A.1 confers, within the limits of the scope of the present document, a presumption of conformity with the corresponding essential requirements of that Directive, and associated EFTA regulations.
National transposition dates Date of adoption of this EN: 17 July 2017 Date of latest announcement of this EN (doa): 31 October 2017 Date of latest publication of new National Standard or endorsement of this EN (dop/e):
30 April 2018 Date of withdrawal of any conflicting National Standard (dow): 30 April 2019
Modal verbs terminology In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and "cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of provisions). "must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation. SIST EN 303 348 V1.1.2:2017
ETSI ETSI EN 303 348 V1.1.2 (2017-07) 6 Introduction Audio Frequency Induction Loop Systems (AFILS) have been on the market since the middle of the twentieth century, with the first recognizable patents appearing circa 1938. AFILS are primarily used to facilitate improved communication to people with impaired hearing and are an important tool in the reduction of discrimination against disabled people. The present document represents the performance of equipment which is currently on the market, which has not previously been subjected to compliance to a "radio" directive. AFILS are installed in places of worship, places of entertainment, places of education, ticket booths and service counters, etc., as well as in domestic situations, providing huge benefits to users with impaired hearing. AFILS provide an audio frequency magnetic field that couples with a receiving coil (Telecoil) fitted in hearing aids, cochlear implants, loop listeners and testing devices. This magnetic field is generated in a wire loop that is fed by an audio frequency amplifier which is capable of driving current through the "induction loop" which, in turn, is fed from external signals such as those generated by microphones, audio-visual equipment and musical instruments. AFILS operate below 9 kHz and have a very limited range (some few metres) and there is no known evidence of interference with radio equipment.
The market for AFILS is relatively small compared with technologies such as RFID, and is physically separated from most radio systems, so the opportunity for mutual interference problems is reduced compared to other users of the spectrum in this frequency range. The present document has been developed in response to Directive 2014/53/EU [i.1], which is the first radio standard that has been produced for AFILS equipment and has been prepared to allow the assessment of audio frequency induction loop amplifiers and receivers for compliance with Directive 2014/53/EU [i.1]. SIST EN 303 348 V1.1.2:2017
ETSI ETSI EN 303 348 V1.1.2 (2017-07) 7 1 Scope The present document specifies technical characteristics and methods of measurements for audio frequency induction loop amplifiers and receivers operating from 10 Hz to 9 kHz used in audio frequency induction loop systems (AFILS). NOTE: The object of an AFILS is to transmit an audio signal to people with hearing difficulties. The receiver in this case is normally a hearing aid with a built in telecoil. These radio equipment types are capable of operating in the frequency band within the 10 Hz to 9 kHz range: • either with an output connection(s) and dedicated loop(s) or with an internal loop(s); • for audio frequency baseband transmission (un-modulated and without the use of a carrier). The present document covers fixed induction loop amplifiers, mobile induction loop amplifiers and portable induction loop amplifiers.
The present document covers the essential requirements of article 3.2 of Directive 2014/53/EU [i.1] under the conditions identified in annex A. 2 References 2.1 Normative references References are specific, identified by date of publication and/or edition number or version number. Only the cited version applies.
Referenced documents which are not found to be publicly available in the expected location might be found at https://docbox.etsi.org/Reference/. NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee their long term validity. The following referenced documents are necessary for the application of the present document. [1] Void. [2] CEPT/ERC/Recommendation 74-01E (Siófok 98, Nice 99, Sesimbra 02, Hradec Kralove 05, Cardiff 11): "Unwanted Emissions in the Spurious Domain". 2.2 Informative references References are either specific (identified by date of publication and/or edition number or version number) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the referenced document (including any amendments) applies. NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee their long term validity. The following referenced documents are not necessary for the application of the present document but they assist the user with regard to a particular subject area. [i.1] Directive 2014/53/EU of the European Parliament and of the Council of 16 April 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of radio equipment and repealing Directive 1999/5/EC. [i.2] CEPT/ERC/REC 70-03: "Relating to the use of Short Range Devices (SRD)". SIST EN 303 348 V1.1.2:2017
ETSI ETSI EN 303 348 V1.1.2 (2017-07) 8 [i.3] CISPR 16-2-3: "Specification for radio disturbance and immunity measuring apparatus and methods - Part 2-3: Methods of measurement of disturbances and immunity - Radiated disturbance measurements". [i.4] IEC 60118-4: "Electroacoustics - Hearing aids - Part 4: Induction loop systems for hearing aid purposes - Magnetic field strength". [i.5] IEC 62489-1 + Amd 1: "Electroacoustics - Audio-frequency induction loop systems for assisted hearing - Part 1: Methods of measuring and specifying the performance of system components". [i.6] IEC 61672-1: "Electroacoustics. Sound level meters. Specifications". [i.7] IEC 60268-10: "Sound system equipment. Methods for specifying and measuring the characteristics of peak programme level meters". [i.8] Commission Implementing Decision C(2015) 5376 final of 4.8.2015 on a standardisation request to the European Committee for Electrotechnical Standardisation and to the European Telecommunications Standards Institute as regards radio equipment in support of Directive 2014/53/EU of the European Parliament and of the Council. [i.9] ETSI TR 100 028 (all parts) (V1.4.1) (12-2001): "Electromagnetic compatibility and Radio spectrum Matters (ERM); Uncertainties in the measurement of mobile radio equipment characteristics". [i.10] ETSI TR 100 028-2 (V1.4.1) (12-2001): "Electromagnetic compatibility and Radio spectrum Matters (ERM); Uncertainties in the measurement of mobile radio equipment characteristics; Part 2". 3 Definitions, symbols and abbreviations 3.1 Definitions For the purposes of the present document, the terms and definitions given in Directive 2014/53/EU [i.1] and the following apply: artificial loop: reduced size radiating dummy load equal to the nominal impedance of the loop specified by the manufacturer Audio Frequency Induction Loop System (AFILS): system including induction loop amplifier(s), microphones and/or other signal sources, in which a magnetic field is created by the flow of audio-frequency current in a conductor arranged in the form of a loop or coil conducted measurements: measurements that are made using a direct connection to the equipment under test customized loop: loop built according to manufacturers' loop design rules inside tested limits dedicated loop: removable loop supplied and type tested with the AFILS equipment, designed as an indispensable part of the equipment NOTE: The loop has been designed or developed for one or more specific types of equipment. It is the combination of dedicated loop and induction loop amplifier that is expected to be compliant with the regulations. hearing aid: personal amplification system, worn entirely on the listener, which is designed to enable a person with impaired hearing to hear more easily hearing instrument: hearing aid or cochlear implant hearing loop system: See AFILS. in band emissions: emissions on a frequency or frequencies which are inside the occupied bandwidth (10 Hz to 9 kHz) SIST EN 303 348 V1.1.2:2017
ETSI ETSI EN 303 348 V1.1.2 (2017-07) 9 induction loop: current carrying loop or coil of an AFILS used to create the magnetic field NOTE: This is equivalent to the term "antenna" used in other ETSI documents and is used in the present document as it is the term commonly understood by the AFILS industry. induction loop amplifier: audio amplifier designed to drive an induction loop NOTE: This is equivalent to the term "transmitter" used in other ETSI documents and is used in the present document as it is the term commonly understood by the AFILS industry. induction loop listener: portable listening device that is designed to give an audible output in response to signals produced by an AFILS induction loop monitor receiver: equipment designed to verify the performance of an AFILS by audio and visual means: a) providing visible indication that it is powered and indicating when the strength of the magnetic field produced by the loop falls within a specified range; and b) providing an audio-frequency output by which the sound quality of the AFILS transmissions can be assessed induction loop system: See AFILS. internal loop: loop designed as a fixed part of the equipment, without the use of an external connector and as such which cannot be disconnected from the equipment by the user loop: See induction loop. loop listener: See induction loop listener. magnetic dipole moment: product of (Number of loop turns) × (loop area) × (loop current) NOTE: Air loops only. magnetic field strength level meter: instrument designed to measure magnetic field strength of audio frequency magnetic fields NOTE: Two types are in common use; a peak-programme meter (PPM) type having dynamic characteristics similar to those of the Type II meter as specified in IEC 60268-10 [i.7], and a true rms meter type that incorporates a true rms rectifier, and meets the relevant requirements for a Class 2 sound level meter as specified in IEC 61672-1 [i.6]. Full functional specifications for both types of meter can be found in IEC 60118-4 [i.4]. mobile amplifier: equipment normally installed in a vehicle out of band emissions: emissions on a frequency or frequencies which are outside the occupied bandwidth (10 Hz to 9 kHz), but for which the levels are in transition to a frequency where the level may be reduced without affecting the corresponding transmission of information phased loop array: system of overlapping loops in which the currents are out of phase with each other portable amplifier: amplifier intended to be carried or attached radiated measurements: measurements which involve the absolute measurement of a radiated field rated load: the load, stated by the manufacturer, to which the amplifier output is connected for measurement purposes reference magnetic field strength level: 0 dB reference for magnetic field strength levels, which is 400 mAm-1 spurious emissions: emissions on a frequency or frequencies which are outside the occupied bandwidth (10 Hz to 9 kHz) and the level of which may be reduced without affecting the corresponding transmission of information telecoil: magnetic pickup coil intended to receive signals from an audio frequency induction loop system NOTE: A telecoil can be part of a hearing aid, cochlear implant, or of any other device for receiving signals from an audio frequency induction loop system in accordance with IEC 60118-4 [i.4]. SIST EN 303 348 V1.1.2:2017
ETSI ETSI EN 303 348 V1.1.2 (2017-07) 10 type designation: manufacturers' marking of the equipment useful magnetic field volume: volume within which the AFILS provides a hearing-aid user with a signal of acceptable quality NOTE: See IEC 60118-4 [i.4]. 3.2 Symbols For the purposes of the present document, the following symbols apply: Ω ohm A loop area C correction factor E elect
...
ETSI EN 303 348 V1.1.2 (2017-07)
HARMONISED EUROPEAN STANDARD
Induction loop systems
intended to assist the hearing impaired
in the frequency range 10 Hz to 9 kHz;
Harmonised Standard covering the essential requirements
of article 3.2 of Directive 2014/53/EU
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2 ETSI EN 303 348 V1.1.2 (2017-07)
Reference
DEN/ERM-TG17WG3-16
Keywords
harmonised standard, hearing aid, inductive
ETSI
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GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.
ETSI
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3 ETSI EN 303 348 V1.1.2 (2017-07)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
Introduction . 6
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 7
3 Definitions, symbols and abbreviations . 8
3.1 Definitions . 8
3.2 Symbols . 10
3.3 Abbreviations . 10
4 Technical requirements specifications . 11
4.1 Environmental conditions . 11
4.1.1 Environmental profile . 11
4.2 General requirements . 11
4.2.1 Presentation of induction loop amplifier equipment for testing purposes . 11
4.2.2 Choice of model for testing . 11
4.2.3 Controls . 11
4.2.4 Amplifier shut-off facility . 12
4.2.5 Declarations by the manufacturer . 12
4.2.6 Auxiliary test equipment . 12
5 Testing for compliance with technical requirements . 12
5.1 Environmental conditions for testing . 12
5.1.1 General requirements . 12
5.1.2 Normal temperature and humidity . 12
5.1.3 Test power source . 12
5.1.3.1 General requirements . 12
5.1.3.2 External test power source . 13
5.1.3.3 Internal test power source . 13
5.1.3.3.1 General . 13
5.1.3.3.2 Mains voltage . 13
5.1.3.3.3 Valve-regulated lead-acid battery power sources . 13
5.1.3.3.4 Other power sources . 13
5.2 General conditions . 13
5.2.1 Normal test signals. 13
5.2.1.1 Signal input for testing . 14
5.2.2 Loop connections . 14
5.2.2.1 General . 14
5.2.2.2 Artificial loop . 14
5.2.3 Measuring receiver . 14
5.3 Induction loop amplifier . 15
5.3.1 General . 15
5.3.2 Induction loop amplifier definitions . 15
5.3.2.1 General . 15
5.3.2.2 Product Classes . 15
5.3.3 Audio frequency in band and out of band emission limits . 16
5.3.3.1 Definition . 16
5.3.3.2 Methods of measurement . 16
5.3.3.3 Limits . 17
5.3.4 Spurious domain emission limits . 17
5.3.4.1 Definition . 17
5.3.4.2 Methods of measurement . 17
ETSI
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4 ETSI EN 303 348 V1.1.2 (2017-07)
5.3.4.3 Limits . 17
5.4 Induction loop receiver . 18
5.4.1 General . 18
5.4.2 Headphone output . 18
5.4.3 Induction loop receiver definitions . 18
5.4.4 Methods of measurement . 18
5.4.5 Limits . 18
5.5 Interpretation of the measurement results . 19
Annex A (informative): Relationship between the present document and the essential
requirements of Directive 2014/53/EU . 20
Annex B (informative): Technical overview . 21
B.1 Induction loop amplifiers . 21
B.1.1 General . 21
B.1.2 Frequency response . 21
B.1.3 Field strength . 21
B.1.4 General performance criteria . 21
B.2 Induction loop receivers and test equipment . 21
B.2.1 General . 21
B.2.2 Sensitivity . 22
Annex C (normative): Measurement . 23
C.1 Standard test position to be used with internal loop equipment or equipment having a loop
connector . 23
Annex D (normative): The relationship between loop current and H-Field strength . 24
Annex E (informative): Artificial loop. 26
Annex F (normative): Induction loop amplifier emission levels and spectrum mask
measurements . 28
Annex G (informative): Determination and use of the measurement bandwidth . 29
Annex H (informative): Bibliography . 30
Annex I (informative): Change history . 31
History . 32
ETSI
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5 ETSI EN 303 348 V1.1.2 (2017-07)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Harmonised European Standard (EN) has been produced by ETSI Technical Committee Electromagnetic
compatibility and Radio spectrum Matters (ERM).
The present document has been prepared under the Commission's standardisation request C(2015) 5376 final [i.8] to
provide one voluntary means of conforming to the essential requirements of Directive 2014/53/EU on the harmonisation
of the laws of the Member States relating to the making available on the market of radio equipment and repealing
Directive 1999/5/EC [i.1].
Once the present document is cited in the Official Journal of the European Union under that Directive, compliance with
the normative clauses of the present document given in table A.1 confers, within the limits of the scope of the present
document, a presumption of conformity with the corresponding essential requirements of that Directive, and associated
EFTA regulations.
National transposition dates
Date of adoption of this EN: 17 July 2017
Date of latest announcement of this EN (doa): 31 October 2017
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 30 April 2018
Date of withdrawal of any conflicting National Standard (dow): 30 April 2019
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI
---------------------- Page: 5 ----------------------
6 ETSI EN 303 348 V1.1.2 (2017-07)
Introduction
Audio Frequency Induction Loop Systems (AFILS) have been on the market since the middle of the twentieth century,
with the first recognizable patents appearing circa 1938. AFILS are primarily used to facilitate improved
communication to people with impaired hearing and are an important tool in the reduction of discrimination against
disabled people.
The present document represents the performance of equipment which is currently on the market, which has not
previously been subjected to compliance to a "radio" directive.
AFILS are installed in places of worship, places of entertainment, places of education, ticket booths and service
counters, etc., as well as in domestic situations, providing huge benefits to users with impaired hearing.
AFILS provide an audio frequency magnetic field that couples with a receiving coil (Telecoil) fitted in hearing aids,
cochlear implants, loop listeners and testing devices. This magnetic field is generated in a wire loop that is fed by an
audio frequency amplifier which is capable of driving current through the "induction loop" which, in turn, is fed from
external signals such as those generated by microphones, audio-visual equipment and musical instruments.
AFILS operate below 9 kHz and have a very limited range (some few metres) and there is no known evidence of
interference with radio equipment.
The market for AFILS is relatively small compared with technologies such as RFID, and is physically separated from
most radio systems, so the opportunity for mutual interference problems is reduced compared to other users of the
spectrum in this frequency range.
The present document has been developed in response to Directive 2014/53/EU [i.1], which is the first radio standard
that has been produced for AFILS equipment and has been prepared to allow the assessment of audio frequency
induction loop amplifiers and receivers for compliance with Directive 2014/53/EU [i.1].
ETSI
---------------------- Page: 6 ----------------------
7 ETSI EN 303 348 V1.1.2 (2017-07)
1 Scope
The present document specifies technical characteristics and methods of measurements for audio frequency induction
loop amplifiers and receivers operating from 10 Hz to 9 kHz used in audio frequency induction loop systems (AFILS).
NOTE: The object of an AFILS is to transmit an audio signal to people with hearing difficulties. The receiver in
this case is normally a hearing aid with a built in telecoil.
These radio equipment types are capable of operating in the frequency band within the 10 Hz to 9 kHz range:
• either with an output connection(s) and dedicated loop(s) or with an internal loop(s);
• for audio frequency baseband transmission (un-modulated and without the use of a carrier).
The present document covers fixed induction loop amplifiers, mobile induction loop amplifiers and portable induction
loop amplifiers.
The present document covers the essential requirements of article 3.2 of Directive 2014/53/EU [i.1] under the
conditions identified in annex A.
2 References
2.1 Normative references
References are specific, identified by date of publication and/or edition number or version number. Only the cited
version applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
[1] Void.
[2] CEPT/ERC/Recommendation 74-01E (Siófok 98, Nice 99, Sesimbra 02, Hradec Kralove 05,
Cardiff 11): "Unwanted Emissions in the Spurious Domain".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] Directive 2014/53/EU of the European Parliament and of the Council of 16 April 2014 on the
harmonisation of the laws of the Member States relating to the making available on the market of
radio equipment and repealing Directive 1999/5/EC.
[i.2] CEPT/ERC/REC 70-03: "Relating to the use of Short Range Devices (SRD)".
ETSI
---------------------- Page: 7 ----------------------
8 ETSI EN 303 348 V1.1.2 (2017-07)
[i.3] CISPR 16-2-3: "Specification for radio disturbance and immunity measuring apparatus and
methods - Part 2-3: Methods of measurement of disturbances and immunity - Radiated disturbance
measurements".
[i.4] IEC 60118-4: "Electroacoustics - Hearing aids - Part 4: Induction loop systems for hearing aid
purposes - Magnetic field strength".
[i.5] IEC 62489-1 + Amd 1: "Electroacoustics - Audio-frequency induction loop systems for assisted
hearing - Part 1: Methods of measuring and specifying the performance of system components".
[i.6] IEC 61672-1: "Electroacoustics. Sound level meters. Specifications".
[i.7] IEC 60268-10: "Sound system equipment. Methods for specifying and measuring the
characteristics of peak programme level meters".
[i.8] Commission Implementing Decision C(2015) 5376 final of 4.8.2015 on a standardisation request
to the European Committee for Electrotechnical Standardisation and to the European
Telecommunications Standards Institute as regards radio equipment in support of Directive
2014/53/EU of the European Parliament and of the Council.
[i.9] ETSI TR 100 028 (all parts) (V1.4.1) (12-2001): "Electromagnetic compatibility and Radio
spectrum Matters (ERM); Uncertainties in the measurement of mobile radio equipment
characteristics".
[i.10] ETSI TR 100 028-2 (V1.4.1) (12-2001): "Electromagnetic compatibility and Radio spectrum
Matters (ERM); Uncertainties in the measurement of mobile radio equipment characteristics;
Part 2".
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in Directive 2014/53/EU [i.1] and the
following apply:
artificial loop: reduced size radiating dummy load equal to the nominal impedance of the loop specified by the
manufacturer
Audio Frequency Induction Loop System (AFILS): system including induction loop amplifier(s), microphones
and/or other signal sources, in which a magnetic field is created by the flow of audio-frequency current in a conductor
arranged in the form of a loop or coil
conducted measurements: measurements that are made using a direct connection to the equipment under test
customized loop: loop built according to manufacturers' loop design rules inside tested limits
dedicated loop: removable loop supplied and type tested with the AFILS equipment, designed as an indispensable part
of the equipment
NOTE: The loop has been designed or developed for one or more specific types of equipment. It is the
combination of dedicated loop and induction loop amplifier that is expected to be compliant with the
regulations.
hearing aid: personal amplification system, worn entirely on the listener, which is designed to enable a person with
impaired hearing to hear more easily
hearing instrument: hearing aid or cochlear implant
hearing loop system: See AFILS.
in band emissions: emissions on a frequency or frequencies which are inside the occupied bandwidth (10 Hz to 9 kHz)
ETSI
---------------------- Page: 8 ----------------------
9 ETSI EN 303 348 V1.1.2 (2017-07)
induction loop: current carrying loop or coil of an AFILS used to create the magnetic field
NOTE: This is equivalent to the term "antenna" used in other ETSI documents and is used in the present
document as it is the term commonly understood by the AFILS industry.
induction loop amplifier: audio amplifier designed to drive an induction loop
NOTE: This is equivalent to the term "transmitter" used in other ETSI documents and is used in the present
document as it is the term commonly understood by the AFILS industry.
induction loop listener: portable listening device that is designed to give an audible output in response to signals
produced by an AFILS
induction loop monitor receiver: equipment designed to verify the performance of an AFILS by audio and visual
means:
a) providing visible indication that it is powered and indicating when the strength of the magnetic field produced
by the loop falls within a specified range; and
b) providing an audio-frequency output by which the sound quality of the AFILS transmissions can be assessed
induction loop system: See AFILS.
internal loop: loop designed as a fixed part of the equipment, without the use of an external connector and as such
which cannot be disconnected from the equipment by the user
loop: See induction loop.
loop listener: See induction loop listener.
magnetic dipole moment: product of (Number of loop turns) × (loop area) × (loop current)
NOTE: Air loops only.
magnetic field strength level meter: instrument designed to measure magnetic field strength of audio frequency
magnetic fields
NOTE: Two types are in common use; a peak-programme meter (PPM) type having dynamic characteristics
similar to those of the Type II meter as specified in IEC 60268-10 [i.7], and a true rms meter type that
incorporates a true rms rectifier, and meets the relevant requirements for a Class 2 sound level meter as
specified in IEC 61672-1 [i.6]. Full functional specifications for both types of meter can be found in
IEC 60118-4 [i.4].
mobile amplifier: equipment normally installed in a vehicle
out of band emissions: emissions on a frequency or frequencies which are outside the occupied bandwidth (10 Hz to
9 kHz), but for which the levels are in transition to a frequency where the level may be reduced without affecting the
corresponding transmission of information
phased loop array: system of overlapping loops in which the currents are out of phase with each other
portable amplifier: amplifier intended to be carried or attached
radiated measurements: measurements which involve the absolute measurement of a radiated field
rated load: the load, stated by the manufacturer, to which the amplifier output is connected for measurement purposes
-1
reference magnetic field strength level: 0 dB reference for magnetic field strength levels, which is 400 mAm
spurious emissions: emissions on a frequency or frequencies which are outside the occupied bandwidth (10 Hz to
9 kHz) and the level of which may be reduced without affecting the corresponding transmission of information
telecoil: magnetic pickup coil intended to receive signals from an audio frequency induction loop system
NOTE: A telecoil can be part of a hearing aid, cochlear implant, or of any other device for receiving signals from
an audio frequency induction loop system in accordance with IEC 60118-4 [i.4].
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10 ETSI EN 303 348 V1.1.2 (2017-07)
type designation: manufacturers' marking of the equipment
useful magnetic field volume: volume within which the AFILS provides a hearing-aid user with a signal of acceptable
quality
NOTE: See IEC 60118-4 [i.4].
3.2 Symbols
For the purposes of the present document, the following symbols apply:
Ω ohm
A loop area
C correction factor
E electrical field str
...
Final draft ETSI EN 303 348 V1.1.1 (2017-05)
HARMONISED EUROPEAN STANDARD
Induction loop systems
intended to assist the hearing impaired
in the frequency range 10 Hz to 9 kHz;
Harmonised Standard covering the essential requirements
of article 3.2 of Directive 2014/53/EU
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2 Final draft ETSI EN 303 348 V1.1.1 (2017-05)
Reference
DEN/ERM-TG17WG3-16
Keywords
harmonised standard, hearing aid, inductive
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3 Final draft ETSI EN 303 348 V1.1.1 (2017-05)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
Introduction . 5
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 7
3 Definitions, symbols and abbreviations . 8
3.1 Definitions . 8
3.2 Symbols . 10
3.3 Abbreviations . 10
4 Technical requirements specifications . 11
4.1 Environmental conditions . 11
4.1.1 Environmental profile . 11
4.2 General requirements . 11
4.2.1 Presentation of induction loop amplifier equipment for testing purposes . 11
4.2.2 Choice of model for testing . 11
4.2.3 Controls . 11
4.2.4 Amplifier shut-off facility . 12
4.2.5 Declarations by the manufacturer . 12
4.2.6 Auxiliary test equipment . 12
5 Testing for compliance with technical requirements . 12
5.1 Environmental conditions for testing . 12
5.1.1 General requirements . 12
5.1.2 Normal temperature and humidity . 12
5.1.3 Test power source . 12
5.1.3.1 General requirements . 12
5.1.3.2 External test power source . 13
5.1.3.3 Internal test power source . 13
5.1.3.3.1 General . 13
5.1.3.3.2 Mains voltage . 13
5.1.3.3.3 Valve-regulated lead-acid battery power sources . 13
5.1.3.3.4 Other power sources . 13
5.2 General conditions . 13
5.2.1 Normal test signals. 13
5.2.1.1 Signal input for testing . 14
5.2.2 Loop connections . 14
5.2.2.1 General . 14
5.2.2.2 Artificial loop . 14
5.2.3 Measuring receiver . 14
5.3 Induction loop amplifier . 15
5.3.1 General . 15
5.3.2 Induction loop amplifier definitions . 15
5.3.2.1 General . 15
5.3.2.2 Product Classes . 15
5.3.3 Audio frequency in band and out of band emission limits . 16
5.3.3.1 Definition . 16
5.3.3.2 Methods of measurement . 16
5.3.3.3 Limits . 17
5.3.4 Spurious domain emission limits . 17
5.3.4.1 Definition . 17
5.3.4.2 Methods of measurement . 17
ETSI
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4 Final draft ETSI EN 303 348 V1.1.1 (2017-05)
5.3.4.3 Limits . 17
5.4 Induction loop receiver . 18
5.4.1 General . 18
5.4.2 Headphone output . 18
5.4.3 Induction loop receiver definitions . 18
5.4.4 Methods of measurement . 18
5.4.5 Limits . 18
5.5 Interpretation of the measurement results . 19
Annex A (informative): Relationship between the present document and the essential
requirements of Directive 2014/53/EU . 20
Annex B (informative): Technical overview . 21
B.1 Induction loop amplifiers . 21
B.1.1 General . 21
B.1.2 Frequency response . 21
B.1.3 Field strength . 21
B.1.4 General performance criteria . 21
B.2 Induction loop receivers and test equipment . 21
B.2.1 General . 21
B.2.2 Sensitivity . 22
Annex C (normative): Measurement . 23
C.1 Standard test position to be used with internal loop equipment or equipment having a loop
connector . 23
Annex D (normative): The relationship between loop current and H-Field strength . 24
Annex E (informative): Artificial loop. 26
Annex F (normative): Induction loop amplifier emission levels and spectrum mask
measurements . 28
Annex G (informative): Determination and use of the measurement bandwidth . 29
Annex H (informative): Bibliography . 30
Annex I (informative): Change history . 31
History . 32
ETSI
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5 Final draft ETSI EN 303 348 V1.1.1 (2017-05)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This final draft Harmonised European Standard (EN) has been produced by ETSI Technical Committee
Electromagnetic compatibility and Radio spectrum Matters (ERM), and is now submitted for the Vote phase of the
ETSI standards EN Approval Procedure.
The present document has been prepared under the Commission's standardisation request C(2015) 5376 final [i.8] to
provide one voluntary means of conforming to the essential requirements of Directive 2014/53/EU on the harmonisation
of the laws of the Member States relating to the making available on the market of radio equipment and repealing
Directive 1999/5/EC [i.1].
Once the present document is cited in the Official Journal of the European Union under that Directive, compliance with
the normative clauses of the present document given in table A.1 confers, within the limits of the scope of the present
document, a presumption of conformity with the corresponding essential requirements of that Directive, and associated
EFTA regulations.
Proposed national transposition dates
Date of latest announcement of this EN (doa): 3 months after ETSI publication
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 6 months after doa
Date of withdrawal of any conflicting National Standard (dow): 18 months after doa
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
Introduction
Audio Frequency Induction Loop Systems (AFILS) have been on the market since the middle of the twentieth century,
with the first recognizable patents appearing circa 1938. AFILS are primarily used to facilitate improved
communication to people with impaired hearing and are an important tool in the reduction of discrimination against
disabled people.
The present document represents the performance of equipment which is currently on the market, which has not
previously been subjected to compliance to a "radio" directive.
ETSI
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6 Final draft ETSI EN 303 348 V1.1.1 (2017-05)
AFILS are installed in places of worship, places of entertainment, places of education, ticket booths and service
counters, etc., as well as in domestic situations, providing huge benefits to users with impaired hearing.
AFILS provide an audio frequency magnetic field that couples with a receiving coil (Telecoil) fitted in hearing aids,
cochlear implants, loop listeners and testing devices. This magnetic field is generated in a wire loop that is fed by an
audio frequency amplifier which is capable of driving current through the "induction loop" which, in turn, is fed from
external signals such as those generated by microphones, audio-visual equipment and musical instruments.
AFILS operate below 9 kHz and have a very limited range (some few metres) and there is no known evidence of
interference with radio equipment.
The market for AFILS is relatively small compared with technologies such as RFID, and is physically separated from
most radio systems, so the opportunity for mutual interference problems is reduced compared to other users of the
spectrum in this frequency range.
The present document has been developed in response to Directive 2014/53/EU [i.1], which is the first radio standard
that has been produced for AFILS equipment and has been prepared to allow the assessment of audio frequency
induction loop amplifiers and receivers for compliance with Directive 2014/53/EU [i.1].
ETSI
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7 Final draft ETSI EN 303 348 V1.1.1 (2017-05)
1 Scope
The present document specifies technical characteristics and methods of measurements for audio frequency induction
loop amplifiers and receivers operating from 10 Hz to 9 kHz used in audio frequency induction loop systems (AFILS).
NOTE: The object of an AFILS is to transmit an audio signal to people with hearing difficulties. The receiver in
this case is normally a hearing aid with a built in telecoil.
These radio equipment types are capable of operating in the frequency band within the 10 Hz to 9 kHz range:
• either with an output connection(s) and dedicated loop(s) or with an internal loop(s);
• for audio frequency baseband transmission (un-modulated and without the use of a carrier);
The present document covers fixed induction loop amplifiers, mobile induction loop amplifiers and portable induction
loop amplifiers.
The present document covers the essential requirements of article 3.2 of Directive 2014/53/EU [i.1] under the
conditions identified in annex A.
2 References
2.1 Normative references
References are specific, identified by date of publication and/or edition number or version number. Only the cited
version applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference/.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
[1] Void.
[2] CEPT/ERC/Recommendation 74-01E (Siófok 98, Nice 99, Sesimbra 02, Hradec Kralove 05,
Cardiff 11): "Unwanted Emissions in the Spurious Domain".
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] Directive 2014/53/EU of the European Parliament and of the Council of 16 April 2014 on the
harmonisation of the laws of the Member States relating to the making available on the market of
radio equipment and repealing Directive 1999/5/EC.
[i.2] CEPT/ERC/REC 70-03: "Relating to the use of Short Range Devices (SRD)".
ETSI
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8 Final draft ETSI EN 303 348 V1.1.1 (2017-05)
[i.3] CISPR 16-2-3: "Specification for radio disturbance and immunity measuring apparatus and
methods - Part 2-3: Methods of measurement of disturbances and immunity - Radiated disturbance
measurements".
[i.4] IEC 60118-4: "Electroacoustics - Hearing aids - Part 4: Induction loop systems for hearing aid
purposes - Magnetic field strength".
[i.5] IEC 62489-1 + Amd 1: "Electroacoustics - Audio-frequency induction loop systems for assisted
hearing - Part 1: Methods of measuring and specifying the performance of system components".
[i.6] IEC 61672-1: "Electroacoustics. Sound level meters. Specifications".
[i.7] IEC 60268-10: "Sound system equipment. Methods for specifying and measuring the
characteristics of peak programme level meters".
[i.8] Commission Implementing Decision C(2015) 5376 final of 4.8.2015 on a standardisation request
to the European Committee for Electrotechnical Standardisation and to the European
Telecommunications Standards Institute as regards radio equipment in support of Directive
2014/53/EU of the European Parliament and of the Council.
[i.9] ETSI TR 100 028 (all parts) (V1.4.1) (12-2001): "Electromagnetic compatibility and Radio
spectrum Matters (ERM); Uncertainties in the measurement of mobile radio equipment
characteristics".
[i.10] ETSI TR 100 028-2 (V1.4.1) (12-2001): "Electromagnetic compatibility and Radio spectrum
Matters (ERM); Uncertainties in the measurement of mobile radio equipment characteristics;
Part 2".
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in Directive 2014/53/EU [i.1] and the
following apply:
artificial loop: reduced size radiating dummy load equal to the nominal impedance of the loop specified by the
manufacturer
Audio-Frequency Induction-Loop System (AFILS): system including induction loop amplifier(s), microphones
and/or other signal sources, in which a magnetic field is created by the flow of audio-frequency current in a conductor
arranged in the form of a loop or coil
conducted measurements: measurements that are made using a direct connection to the equipment under test
customized loop: loop built according to manufacturers' loop design rules inside tested limits
dedicated loop: removable loop supplied and type tested with the AFILS equipment, designed as an indispensable part
of the equipment
NOTE: The loop has been designed or developed for one or more specific types of equipment. It is the
combination of dedicated loop and induction loop amplifier that is expected to be compliant with the
regulations.
hearing aid: personal amplification system, worn entirely on the listener, which is designed to enable a person with
impaired hearing to hear more easily
hearing instrument: hearing aid or cochlear implant
hearing loop system: See AFILS.
in band emissions: emissions on a frequency or frequencies which are inside the occupied bandwidth (10 Hz to 9 kHz)
induction loop: current carrying loop or coil of an AFILS used to create the magnetic field
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9 Final draft ETSI EN 303 348 V1.1.1 (2017-05)
NOTE: This is equivalent to the term "antenna" used in other ETSI documents and is used in the present
document as it is the term commonly understood by the AFILS industry.
induction loop amplifier: audio amplifier designed to drive an induction loop
NOTE: This is equivalent to the term "transmitter" used in other ETSI documents and is used in the present
document as it is the term commonly understood by the AFILS industry.
induction loop listener: portable listening device that is designed to give an audible output in response to signals
produced by an AFILS
induction loop monitor receiver: equipment designed to verify the performance of an AFILS by audio and visual
means:
a) providing visible indication that it is powered and indicating when the strength of the magnetic field produced
by the loop falls within a specified range; and
b) providing an audio-frequency output by which the sound quality of the AFILS transmissions can be assessed
induction-loop system: See AFILS.
internal loop: loop designed as a fixed part of the equipment, without the use of an external connector and as such
which cannot be disconnected from the equipment by the user
loop: See induction loop.
loop listener: See induction-loop listener.
magnetic dipole moment: product of (Number of loop turns) × (loop area) × (loop current)
NOTE: Air loops only.
magnetic field strength level meter: instrument designed to measure magnetic field strength of audio frequency
magnetic fields
NOTE: Two types are in common use; a peak-programme meter (PPM) type having dynamic characteristics
similar to those of the Type II meter as specified in IEC 60268-10 [i.7], and a true rms meter type that
incorporates a true rms rectifier, and meets the relevant requirements for a Class 2 sound level meter as
specified in IEC 61672-1 [i.6]. Full functional specifications for both types of meter can be found in
IEC 60118-4 [i.4].
mobile amplifier: equipment normally installed in a vehicle
out of band emissions: emissions on a frequency or frequencies which are outside the occupied bandwidth (10 Hz to
9 kHz), but for which the levels are in transition to a frequency where the level may be reduced without affecting the
corresponding transmission of information
phased loop array: system of overlapping loops in which the currents are out of phase with each other
portable amplifier: amplifier intended to be carried or attached
radiated measurements: measurements which involve the absolute measurement of a radiated field
rated load: the load, stated by the manufacturer, to which the amplifier output is connected for measurement purposes
-1
reference magnetic field strength level: 0 dB reference for magnetic field strength levels, which is 400 mAm
spurious emissions: emissions on a frequency or frequencies which are outside the occupied bandwidth (10 Hz to
9 kHz) and the level of which may be reduced without affecting the corresponding transmission of information
telecoil: magnetic pickup coil intended to receive signals from an audio-frequency induction-loop system
NOTE: A telecoil can be part of a hearing aid, cochlear implant, or of any other device for receiving signals from
an audio-frequency induction-loop system in accordance with IEC 60118-4 [i.4].
type designation: manufacturers' marking of the equipment
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10 Final draft ETSI EN 303 348 V1.1.1 (2017-05)
useful magnetic field volume: volume within which the AFILS
...
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