SIST EN ISO 389-3:1999
(Main)Acoustics - Reference zero for the calibration of audiometric equipment - Part 3: Reference equivalent threshold force levels for pure tones and bone vibrators (ISO 389-3:1994)
Acoustics - Reference zero for the calibration of audiometric equipment - Part 3: Reference equivalent threshold force levels for pure tones and bone vibrators (ISO 389-3:1994)
Specifies the following data applicable to the calibration of bone vibrators for pure-tone bone-conduction audiometry: reference equivalent threshold force levels (RETFL), corresponding to the threshold of hearing of young otologically normal persons by bone-conduction audiometry; essential characteristics of the bone vibrator and of its method of coupling to a person under test and to the mechanical coupler; essential characteristics and datum level of the masking noise applied to the ear not under test.
Akustik - Standard-Bezugspegel für die Kalibrierung audiometrischer Geräte - Teil 3: Äquivalente Bezugs-Schwellenkraftpegel für reine Töne und Knochenleitungshöher (ISO 389-3:1994)
Dieser Teil der ISO 389 legt folgende für die Kalibrierung von Knochenleitungshörern in der Reinton-Knochenleitungs-Audiometrie anwendbare Daten fest: a)Äquivalente Bezugs-Schwellenkraftpegel, die den durch Knochenleitungs-Audiometrie bestimmten Hörschwellenpegeln von jungen, otologisch normalen Personen entsprechen. Der äquiva-lente Bezugs-Schwellenkraftpegel ist der Pegel der periodischen Kraft, die auf den mechanischen Kuppler mit bestimmten Eigenschaften (siehe 5.3) von einem Knochenleitungshörer übertragen wird,
Acoustique - Zéro de référence pour l'étalonnage d'équipements audiométriques - Partie 3: Niveaux de référence équivalents de force liminaire pour les vibrateurs a sons purs et les ossivibrateurs (ISO 389-3:1994)
Akustika - Referenčna ničla za umerjanje avdiometrov - 3. del: Referenčne ekvivalentne ravni za prag sile za čiste tone in dajalnike za kostno prevodnost (ISO 389-3:1994)
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 389-3:1999
01-november-1999
$NXVWLND5HIHUHQþQDQLþOD]DXPHUMDQMHDYGLRPHWURYGHO5HIHUHQþQH
HNYLYDOHQWQHUDYQL]DSUDJVLOH]DþLVWHWRQHLQGDMDOQLNH]DNRVWQRSUHYRGQRVW,62
Acoustics - Reference zero for the calibration of audiometric equipment - Part 3:
Reference equivalent threshold force levels for pure tones and bone vibrators (ISO 389-
3:1994)
Akustik - Standard-Bezugspegel für die Kalibrierung audiometrischer Geräte - Teil 3:
Äquivalente Bezugs-Schwellenkraftpegel für reine Töne und Knochenleitungshöher (ISO
389-3:1994)
Acoustique - Zéro de référence pour l'étalonnage d'équipements audiométriques - Partie
3: Niveaux de référence équivalents de force liminaire pour les vibrateurs a sons purs et
les ossivibrateurs (ISO 389-3:1994)
Ta slovenski standard je istoveten z: EN ISO 389-3:1998
ICS:
13.140 Vpliv hrupa na ljudi Noise with respect to human
beings
SIST EN ISO 389-3:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 389-3:1999
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SIST EN ISO 389-3:1999
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SIST EN ISO 389-3:1999
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SIST EN ISO 389-3:1999
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SIST EN ISO 389-3:1999
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SIST EN ISO 389-3:1999
INTERNATIONAL
ISO
STANDARD 389-3
First edition
1994-10-01
Acoustics - Reference zero for the
calibration of audiometric equipment -
Part 3:
Reference equivalent threshold forte levels for
pure tones and bone Vibrators
Acoustique - Zero de reference pour Mtalonnage d ‘equipemen ts
audiome triques -
Partie 3: Niveaux de reference Äquivalents de forte liminaire pour les
vibra teurs a sons purs et les ossivibra teurs
Reference number
ISO 389-3:1994(E)
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SIST EN ISO 389-3:1999
ISO 389-3: 1994(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide
federation of national Standards bodies (ISO member bodies). The work
of preparing International Standards is normally carried out through ISO
technical committees. Esch member body interested in a subject for
which a technical committee has been established has the right to be
represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard ISO 389-3 was prepared by Technical Committee
lSO/rC 43, Acoustics.
This first edition of ISO 389-3 cancels and replaces ISO 7566:1987, of
which it is a minor revision.
ISO 389 consists of the following Parts, under the general title Acoustics
- Reference zero for the calibration of audiometric equipment:
- Part 7: ßeference equivalent threshold Sound pressure levels for
pure tones and supra-aural earphones
- Part 2: Reference equivalent threshold Sound pressure levels for
pure tones and insert earphones
- Part 3: ßeference equivalent threshold forte levels for pure tones
and bone Vibrators
- Part 4: Reference levels for narrow-band masking noise
- Part 5: Reference equivalent threshold Sound pressure levels for
pure tones in the frequency range 8 kHz to 16 kHz
- Part 6: Reference equivalent threshold Sound pressure levels for
acoustic test Signals of short duration
0 ISO 1994
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronie or mechanical, including photocopying and
microfilm, without Permission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-l 211 Geneve 20 l Switzerland
Printed in Switzerland
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SIST EN ISO 389-3:1999
0 ISO
ISO 389-3: 1994(E)
- Part 7: ßeference threshold of hearing under free-field and diffuse-
field listening conditions
Part 1 will be a re-issue of ISO 389:1991.
Annexes A, B, C, D and E of this part of ISO 389 are for information only.
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SIST EN ISO 389-3:1999
ISO 389-3: 1994(E) 0 ISO
Introduction
Esch part of ISO 389 specifies a specific reference zero for the calibration
of audiometric equipment. ISO 389:1991 (to be re-issued as ISO 389-1)
and ISO 389-2 are applicable to audiometric equipment for the trans-
mission of pure tones by air conduction.
For clinical diagnostic and other audiometric purposes, it is often necess-
ary to compare the measured hearing threshold levels of a person for
Sound transmitted to the inner ear by the air-conduction and bone-
conduction pathways, respectively. Bone-conducted Sound is provided for
this purpose by an electromechanical Vibrator applied to the mastoid
prominente or to the forehead of the person under test.
The reference zero for the calibration of audiometric equipment for air
conduction is defined in ISO 389:1991 and ISO 389-2 in terms of refer-
ence equivalent threshold Sound pressure levels (RETSPLs), i.e. threshold
Sound pressure Ievels produced in a coupler, ear Simulator or artificial ear
of specified characteristics by supra-aural or insert earphones of various
Patterns, when excited electrically at a level corresponding to the thresh-
old of hearing of young otologically normal persons. Similarly, this part of
ISO 389 provides a reference zero for bone-conduction audiometry in
terms of reference equivalent threshold forte levels (RETFLs), i.e. the vi-
bratory forte levels produced by a bone Vibrator on a specified mechanical
coupler when the Vibrator is excited electrically at a Ievel corresponding
to the threshold of hearing of young otologically normal persons. In some
countries, the preferred location is the mastoid prominente; in other
countries, the forehead location is used in addition to the mastoid promi-
nence. Different RETFL values are valid for each of the two positions (see
annex C).
For bone-conduction measurements, it is necessary to specify the static
forte of application of the Vibrator to the skull of the test subject and to
the mechanical coupler, as well as certain geometrical features of the vi-
brator tip. In addition, it is usually necessary to apply masking noise to the
ear not under test, since excitation of the skull by the Vibrator may be
heard by that ear instead of (or in addition to) the ear intended for the test.
An appropriate specification of the masking noise is, therefore, required
as an adjunct to the reference equivalent threshold forte levels, and such
a specification is given in this part of ISO 389. Due to the so-called “oc-
clusion effect” whereby the wearing of the transducer needed to provide
the (air-conducted) masking noise Causes a lowering of the bone-
conduction threshold of hearing of the ear receiving the masking Signal, it
is necessary for the level of masking noise to be raised to cancel out the
occlusion effect and provide adequate masking of the ear not under test.
The specification of masking noise given in this part of ISO 389 is based
on the procedures used in the experimental investigations from which the
reference zero of this part of ISO 389 is derived.
Use of th is reference Zero to ca i brate audiomet ,ers will
ens ure that
measured bo ne-conduction hearing thresh old levels of pers ons with
un-
iv
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SIST EN ISO 389-3:1999
0 ISO
ISO 389-3: 1994(E)
impaired hearing or with hearing losses of purely sensorineural type
(i.e. having unimpaired outer and middle ear function) will be compatible
with the air-conduction hearing threshold Ievels of the same persons when
using the reference zero of ISO 389:1991 or ISO 389-2, respectively. Al-
though exact equivalence of air-conduction and bone-conduction thresh-
olds for any individual in these classes cannot be expected, due to
biological variability of Sound tansmission through the external and middle
ear and through the skull, this part of ISO 389 will ensure that systematic
deviations averaged over groups of such persons are reduced to a practical
minimum.
This part of ISO 389 is based on an assessment of technical data provided
by Iaboratories in three countries using methods of threshold testing
which, in the respects described, were essentially uniform. Examination
of the data showed that the experimental results were consistent. lt has,
therefore, been possible to standardize a reference zero by means of
RETFL values which are to be used for all bone Vibrators used in
audiometry having similar characteristics to those used by the laboratories.
The systematic uncertainties introduced by this deliberate simplification
will be small in comparison to the usual step size of hearing level controls
in clinical audiometers (5 dB).
V
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SIST EN ISO 389-3:1999
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SIST EN ISO 389-3:1999
ISO 389-3: 1994(E)
INTERNATIONAL STANDARD 0 ISO
Acoustics - Reference zero for the calibration of
audiometric equipment -
Part 3:
Reference equivalent threshold forte levels for pure tones
and bone Vibrators
Guidance on the practical application of this part of
1 Scope
ISO 389 in the calibration of audiometers is given in
annex B.
This part of ISO 389 specifies the following data ap-
plicable to the calibration of bone Vibrators for pure-
NOTE 2 Recommended procedures for carrying out
tone bone-conduction audiometry. bone-conduction audiometry are specified in ISO 8253-1.
a) Reference equivalent threshold forte levels
(RETFLs), corresponding to the threshold of hear-
2 Normative references
ing of young otologically normal persons by
bone-conduction audiometry. RETFL is the vibra-
The following Standards contain provisions which,
tot-y forte level transmitted to a mechanical cou-
through reference in this text, constitute provisions
pler of specified characteristics (see 5.3) by a
of this part of ISO 389. At the time of publication, the
Vibrator when applied to the mechanical coupler
editions indicated were valid. All Standards are subject
under stated conditions of test and when ener-
to revision, and Parties to agreements based on this
gized at the voltage level corresponding to the
patt of ISO 389 are encouraged to investigate the
normal threshold of hearing for location on the
possibility of applying the most recent editions of the
mastoid prominente.
Standards indicated below. Members of IEC and ISO
maintain registers of currently valid International
NOTE 1 Interim values for the differentes in refer-
Standards.
ence equivalent threshold forte levels between location
on the forehead and mastoid arc. included for infor-
ISO 389:1991, Acoustics - Standard reference zero
mation in annex C.
for the calibration of pure-tone air conduction
audiometers. “)
b) Essential characteristics of the bone Vibrator and
ISO 389-2: 1994, Acoustics - ßeference zero for the
of its method of coupling to a person under test
calibra tion of audiometric equipment - Part 2: Ref-
and to the mechanical coupler.
erence equivalent threshold Sound pressure levels for
pure tones and Insert earphones.
c) Essential characteristics and datum level of the I EC 373: 1990, Mechanical coupler for measurements
masking noise applied to the ear not under test. on bone Vibrators.
1) To be re-issued as ISO 389-1.
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SIST EN ISO 389-3:1999
0 ISO
ISO 389-3: 1994(E)
threshold forte level (or reference equivalent thresh-
3 Definitions
old Sound pressure level) for bone conduction or air
conduction, as applicable.
For the purposes of this part of ISO 389, the defi-
nitions given in ISO 389:1991 and ISO 389-2 and the
NOTE 4 By extension, this definition may be applied to
following definitions apply.
a narrow band of noise.
3.1 bone conduction: Transmission of Sound to the
3.8 occlusion effect: Lowering of the hearing
inner ear primarily by means of mechanical Vibration
threshold Ievel of a given ear, stimulated by bone
of the cranial bones.
conduction, when an earphone or earplug is placed
over or in the entrance to the ear canal, thereby
3.2 bone Vibrator: Electromechanical transducer in-
forming an enclosed air volume in the external ear.
tended to produce the Sensation of hearing by vibrat-
The effect is greatest at low frequencies.
ing the cranial bones.
3.9 masking:
3.3 alternating forte level (forte level) (of a vi-
bration): Forte level, in decibels, which is 20 times the
(1) Process by which the threshold of hearing of a
common Iogarithm of the ratio of the r.m.s. value of
Sound is raised by the presence of another (masking)
the forte transmitting the Vibration to the reference
Sound.
value, 1 pN.
(2) Amount by which the hearing threshold level is
3.4 mechanical coupler: Device designed to pre-
so raised, expressed in decibels.
sent a specified mechanical impedance to a bone vi-
brator applied with a specified static forte and
3.10 datum level of masking noise: Level, ex-
equipped with a mechano-electric transducer to de-
pressed as hearing level (see note to 3.7) of a one-
termine the alternating forte level at the surface of
third-octave band of noise delivered by air conduction
contact between a Vibrator and mechanical coupler
in the presence of which a pure tone at the centre
frequency of the noise band and at a hearing Ievel of
NOTE 3 A mechanical coupler is specified in IEC 373.
35 dB is just audible, on the basis of 50 % detection
in repeated trials by an otologically normal person,
35 . equivalent threshold forte level (monaural is-
having zero hearing threshold level by air conduction
tening): For a given ear, at a specified frequency, for
for that pure tone.
a specified configuration of bone Vibrator and for a
stated forte of application of the bone Vibrator to the
NOTES
human mastoid bone, the alternating forte Ievel set
up by the bone Vibrator on a specified mechanical
5 The value of 35 dB has been adopted arbitrarily as lying
coupler when the bone Vibrator is actuated by that
within the range used in experimental studies on which this
part of ISO 389 is based. lt does not imply a recommen-
voltage which, with the bone Vibrator applied to the
dation to adopt this level of masking noise in clinical prac-
mastoid bone concerned, would correspond to the
tice.
threshold of hearing.
6 The relationship between the levels of a masking noise
3.6 reference equivalent threshold forte level
and a pure tone just masked by the presence of this noise
(RETFL): At a specified frequency, the mean value of
is specified in ISO 389-4.
the equivalent threshold forte Ievels of a sufficiently
large number of ears of otologically normal persons,
3.11 critical bandwidth: Widest frequency band
of both sexes, aged between 18 and 30 years inclus-
within which the loudness of a band of continuously
ive, expressing the threshold of hearing in a specified
distributed random noise of constant band Sound
mechanical coupler for a specified configuration of
pressure level is independent of its bandwidth.
bone Vibrator.
3.12 vibrotactile threshold level: Level of an alter-
3.7 hearing level (of a pure tone): At a specified
nating forte at which a person gives 50 % of correct
frequency, for a specific type of transducer and for a
detection responses on repeated trials due to the
specified manner of application, the alternating forte
Sen
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