IEC 60704-3:2019

Household and similar electrical appliances - Test code for the determination of airborne acoustical noise - Part 3: Procedure for determining and verifying declared noise emission values

IEC 60704-3:2019 describes procedures for determining and verifying the declared values of the noise emitted by household and similar appliances. It applies to all categories of household and similar electrical appliances covered by IEC 60704-1 and all parts of IEC 60704-2, which include particular requirements for special categories of appliances. It applies to appliances being produced in quantity, such as in batches, series or lots, which are manufactured to the same technical specification and characterized by the same declared value of noise emission. This part of IEC 60704:
– considers the term "declaration" to include all means for providing information on the noise emission values to potential users (consumers) of the appliances; this includes labels, brochures, advertisements, commercial and technical information papers, etc.;
– considers the declaration for appliances manufactured by mass production;
– specifies a simple statistical method for verifying the declared values by investigating a sample of only three appliances.
This International Standard is to be used in conjunction with IEC 60704-1:2010 and the latest edition of IEC 60704-2 (all parts).
This third edition cancels and replaces the second edition published in 2006. This edition constitutes a technical revision. It includes the following significant technical changes with respect to the previous edition:
a) in Annex A, standard deviations that are now specified for various appliance categories in the parts of IEC 60704-2 have been excluded from Table A.1;
b) furthermore, this edition makes reference to new standards and is implementing ISO/IEC Directives, Part 2 in a more accurate manner.

Appareils électrodomestiques et analogues - Code d’essai pour la détermination du bruit aérien - Partie 3 : Méthode de détermination et de vérification des valeurs déclarées d'émission sonore

L'IEC 60704-3:2019 décrit les méthodes de détermination et de vérification des valeurs déclarées du bruit émis par les appareils domestiques et analogues. Elle s'applique à toutes les catégories d'appareils à usage domestique et analogue couverts par l'IEC 60704-1 et toutes les parties de l'IEC 60704-2, qui contiennent des exigences particulières applicables à certaines catégories d'appareils. Elle s'applique aux appareils produits en quantité (en série, en lots) fabriqués suivant les mêmes spécifications techniques et caractérisés par la même valeur déclarée d'émission sonore. La présente partie de l'IEC 60704:
– utilise le terme "déclaration" pour englober tous les moyens utilisés pour fournir des informations sur les valeurs d'émission sonore aux utilisateurs potentiels (consommateurs) des appareils; ce terme inclut les étiquettes, les notices, les publicités, les fiches techniques et commerciales d'information, etc.;
– traite de la déclaration pour des appareils fabriqués en série;
– décrit une méthode statistique simple pour vérifier les valeurs déclarées en étudiant un échantillon limité à trois appareils.
Cette Norme internationale doit être utilisée conjointement avec l'IEC 60704-1:2010 et la dernière édition de l'IEC 60704-2 (toutes les parties).
Cette troisième édition annule et remplace la deuxième édition parue en 2006. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) dans l'Annexe A, les écarts-types qui sont à présent spécifiés pour différentes catégories d'appareils dans les parties de l'IEC 60704-2 ont été exclus du Tableau A.1;
b) en outre, cette édition fait référence à de nouvelles normes et met en application les Directives ISO/IEC, Partie 2 d'une manière plus précise.

General Information

• Status: Published
• Publication Date: 27-May-2019
• ICS: 17.140.20 - Noise emitted by machines and equipment
• ICS: 97.030 - Domestic electrical appliances in general
• Technical Committee: TC 59 - Performance of household and similar electrical appliances
• Drafting Committee: JWG 2 - TC 59/JWG 2
• Current Stage: PPUB - Publication issued
• Start Date: 28-May-2019
• Completion Date: 26-Jun-2019

Relations

• Revises: IEC 60704-3:2006 - Household and similar electrical appliances - Test code for the determination of airborne acoustical noise - Part 3: Procedure for determining and verifying declared noise emission values
• Effective Date: 05-Sep-2023

Overview - IEC 60704-3:2019 (Noise emission verification)

IEC 60704-3:2019 is the IEC test-code part that specifies how to determine and verify declared noise emission values for household and similar electrical appliances. It is intended for appliances produced in quantity (batches, series or lots) and complements IEC 60704-1 (general measurement requirements) and the relevant parts of IEC 60704-2 (particular requirements). The standard treats a "declaration" broadly - labels, brochures, advertisements and technical papers - and defines a simple statistical verification method that can be applied with a sample of only three appliances.

Key topics and technical requirements

• Scope and applicability: Applies to all appliance categories covered by IEC 60704-1 and IEC 60704-2; focused on mass-produced items with a single declared noise value per lot.
• Measurement basis: Uses test methods and A-weighted sound power level determinations defined in IEC 60704-1 and applicable IEC 60704-2 parts.
• Declared value definition: Specifies how a declared noise emission value (rounded to the nearest decibel) represents an upper statistical bound for a production batch.
• Statistical verification: Presents a simple statistical procedure for verifying declared values by sampling three appliances. The procedure is designed so that, under specified assumptions, a batch has a 95% probability of acceptance when no more than 6.5% of items exceed the declared value.
• Reference standard deviation: Provides guidance on using a reference total standard deviation; Annex A lists standard deviations (with recent changes to align with part‑2 documents).
• Documentation and presentation: Defines how noise emission values should be presented in declarations and where to reference supporting measurement standards.
• Annexes: Includes examples for both verification and determination procedures (informative examples in Annex B and C).

Practical applications

• Product noise labeling and marketing claims verification
• Factory acceptance testing and quality control for noise performance
• Laboratory test procedures for deriving declared A-weighted sound power levels
• Market surveillance sampling and compliance checks (note: standard does not impose a mandatory surveillance strategy)
• Supporting documentation for product datasheets, technical files and consumer information

Who uses this standard

• Appliance manufacturers and R&D teams for product development and declared value assignment
• Accredited test laboratories performing acoustical noise measurements
• Conformity assessment bodies and market surveillance authorities undertaking batch verification
• Product managers and regulatory affairs personnel preparing labels and technical literature

Related standards

• IEC 60704-1 - General requirements for airborne acoustical noise tests
• IEC 60704-2 (all parts) - Particular requirements for specific appliance categories
• ISO 3534-1, ISO 7574-4 - Statistical and terminology references used in the procedures

Keywords: IEC 60704-3:2019, noise emission, household appliances, acoustical noise, declared noise emission values, verification procedure, A-weighted sound power level, IEC 60704.

Standards Content (Sample)

IEC 60704-3 ®
Edition 3.0 2019-05
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Household and similar electrical appliances – Test code for the determination
of airborne acoustical noise –
Part 3: Procedure for determining and verifying declared noise emission values

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IEC 60704-3 ®
Edition 3.0 2019-05
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Household and similar electrical appliances – Test code for the determination

of airborne acoustical noise –

Part 3: Procedure for determining and verifying declared noise emission values

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 17.140.20; 97.030 ISBN 978-2-8322-7027-1

– 2 – IEC 60704-3:2019 RLV © IEC 2019
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and calculations . 6
3.1 Terms and definitions . 6
3.2 Calculations . 12
4 General . 13
4.1 Test method . 13
4.2 Values and symbols . 13
4.3 Reference standard deviation . 14
5 Verification of declared noise emission values . 14
5.1 Basis of the procedure . 14
5.2 Verification procedure . 14
6 Determination of noise emission values for declaration . 15
6.1 Basis of the procedure . 15
6.2 Determination procedure . 15
6.3 Presentation of noise emission values . 15
Annex A (normative) Noise emission of household appliances – Standard deviations . 16
Annex B (informative) Verification of noise emission values – Examples . 17
B.1 Example 1 . 17
B.2 Example 2 . 17
Annex C (informative) Determination of noise emission values – Examples . 18
C.1 Example 1 . 18
C.2 Example 2 . 18
C.3 Example 3 . 19
Bibliography . 21

Figure 1 – Quantile of the standardized distribution . 14

Table A.1 – Standard deviation . 16
Table C.1 – Calculated noise emission values as a function of the total standard
deviation σ and the probability of acceptance P as assumed by the labeller . 18
t a
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
TEST CODE FOR THE DETERMINATION OF AIRBORNE
ACOUSTICAL NOISE –
Part 3: Procedure for determining and verifying
declared noise emission values

FOREWORD
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– 4 – IEC 60704-3:2019 RLV © IEC 2019
International Standard IEC 60704-3 has been prepared by IEC technical committee 59:
Performance of household electrical appliances.
IEC 60704-1:2010 has served as a basis for the elaboration of this standard.
This third edition cancels and replaces the second edition published in 2006. This edition
constitutes a technical revision. It includes the following significant technical changes with
respect to the previous edition:
a) in Annex A, standard deviations that are now specified for various appliance categories in
the parts of IEC 60704-2 have been excluded from Table A.1;
b) furthermore, this edition makes reference to new standards and is implementing
ISO/IEC Directives, Part 2 in a more accurate manner.
Standard deviations specified in part 2 documents of the IEC 60704 series supersede the
values given in Table A.1.
The text of this International Standard is based on the following documents:
CDV Report on voting
59/675/CDV 59/680A/RVC
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
This International Standard is to be used in conjunction with IEC 60704-1:2010 and the latest
edition of IEC 60704-2 (all parts).
A list of all parts in the IEC 60704 series, published under the general title Household and
similar electrical appliances – Test code for the determination of airborne acoustical noise,
can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.

INTRODUCTION
Although the noise levels produced by household appliances are not known to present
a hazard to the hearing of users or other exposed persons, and as a result no noise limits
have been specified by relevant authorities responsible for health protection, A
comprehensive and correct declaration of noise emission will be is very helpful to enable the
potential buyer to make a good choice between appliances of the same category (serving for
the same purpose) of different makes or for different models.
In order to ensure a correct declaration of noise emission values, this part of IEC 60704
prescribes describes a simple method for verifying declared values and provides information
for determining the noise emission values.
The necessary measurements are carried out according to the relevant parts of IEC 60704.
Different countries are implementing different market surveillance strategies. This document
is not implementing a mandatory market surveillance strategy.

– 6 – IEC 60704-3:2019 RLV © IEC 2019
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
TEST CODE FOR THE DETERMINATION OF AIRBORNE
ACOUSTICAL NOISE –
Part 3: Procedure for determining and verifying
declared noise emission values

1 Scope
This part of IEC 60704 describes procedures for determining and verifying the declared
values of the noise emitted by household and similar appliances.
It applies to all categories of household and similar electrical appliances covered by
IEC 60704-1 and all parts of IEC 60704-2 dealing with, which include particular requirements
for special categories of appliances.
It applies to appliances being produced in quantity, such as in batches, series or lots, which
are manufactured to the same technical specification and characterized by the same labeled
declared value of noise emission.
This part of IEC 60704:
– considers the term "declaration" to include all means for providing information on the noise
emission values to potential users (consumers) of the appliances; this includes labels,
brochures, advertisements, commercial and technical information papers, etc.;
– considers the declaration for appliances manufactured by mass production, with the same
declared value for the lot (batch);
– specifies a simple statistical method for verifying the declared values by investigating a
sample of only three appliances.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC 60704-1:19972010, Household and similar electrical appliances – Test code for the
determination of airborne acoustical noise – Part 1: General requirements
IEC 60704-2 (all parts), Household and similar electrical appliances – Test code for the
determination of airborne acoustical noise – Part 2: Particular requirements
ISO 3534-1:19932006, Statistics – Vocabulary and symbols – Part 1: Probability and general
statistical terms
ISO 7574-4:1985, Acoustics – Statistical methods for determining and verifying stated noise
emission values of machinery and equipment – Part 4: Methods for stated values for batches
of machines
3 Terms, definitions and calculations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60704-1 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
sound power level
L
W
ten times the logarithm to the base 10 of the ratio of the sound power of a source to the
reference sound power, expressed in decibels
W
L = 10 lg
dB
W
W
−12
Note 1 to entry: The reference sound power is 1 pW (10 W). The frequency weighting, or the midband
frequency of the frequency band used, is indicated in the symbol.
L
Note 2 to entry: For example, the A-weighted sound power level is .
WA
3.1.2
A-weighted sound power level
L
WA
sound power level of an appliance, in decibels, determined according to the appropriate
requirements specified in IEC 60704-1 and the relevant part of IEC 60704-2
Note 1 to entry: Henceforth, the subscript is left out for reasons of simplicity.
WA
3.1.3
noise emission value
single value of the noise emission quantity
3.1.4
measured value
L
i
noise emission value for an individual appliance determined in accordance with the
appropriate requirements of IEC 60704
3.1.5
family of appliances
category of appliances
appliances of similar design or type, or intended to perform the same functions
[SOURCE: ISO 7574-1:1985, 3.5, modified – The notes have been deleted, "category of
appliances" has been added as a preferred term, "machines" has been replaced by
"appliances" in the term and in the definition, and "or equipment" has been deleted from the
definition.]
3.1.6
declared value
L
c
value of the noise emission quantity which is rounded to the nearest decibel stated for all
appliances of a complete series of production or of a batch thereof, when the appliances are
new
Note 1 to entry: The declared value indicates the upper statistical value below which a specified large proportion
of noise emission values of the relevant batch lies. L depends on the specified verification procedure, which is
c
designed such that there is a probability of acceptance of 95 % for the batch, when no more than 6,5 % of all noise
emission values exceeds L , and if the specified reference standard deviations σ equals the actual total standard
c M
deviation σ .
t
[SOURCE: ISO 7574-1:1985, 3.6, modified – The term "stated value; labelled value" has been
replaced by "declared value"; the first sentence has been rephrased to "which is rounded to

– 8 – IEC 60704-3:2019 RLV © IEC 2019
the nearest decibel stated for all appliances of a complete series of production or of a batch
thereof" and "when the appliances are new" has been added; the second sentence has been
deleted; the fact "are new" is integrated in first sentence and notes 1 and 2 have been
replaced by a Note 1 to entry.]
3.1.7
declaration
statement of the declared value, L , which is included in brochures, advertisements, product
c
or commercial literature and/or affixed to an appliance or part thereof for providing information
on the noise emission values to potential users (buyers, consumers) of the appliance
Note 1 to entry: The term "labeller" is used in this document for a person making declarations.
[SOURCE: ISO 7574-1:1985, 3.7, modified – The term "label" has been replaced by
"declaration", "brochures, advertisements, or commercial literature" have been added, the
phrase after "and/or affixed" has been replaced by "to an appliance or part thereof for
providing information on the noise emission values to potential users (buyers, consumers) of
the appliance" and Note 1 to entry has been added.]
3.1.8
batch of appliances
group of the same family produced in quantity, manufactured to the same technical
specifications and characterized by the same declared value, L
c
Note 1 to entry: A batch may be either an entire production series or a portion thereof.
[SOURCE: ISO 7574-1:1985, 3.8, modified – The term "batch (lot) of machines" has been
replaced by "batch of appliances" and the note has been transferred into Note 1 to entry.]
3.1.9
size of the batch
size of the population
N
number of items (appliances in the batch or noise emission values in the population) of the
batch (or of the population)
[SOURCE: ISO 7574-1:1985, 3.9, modified – The term "size of the population" has been
explicitely added as a preferred term, word "machines" is replaced by "appliances" and
phrase "of the batch (or of the population)" is added.]
3.1.10
sample
one or more appliances (or measured values) randomly selected from a lot (or population)
[SOURCE: ISO 7574-1:1985, 3.10, modified – "Machines" is replaced by "appliances".]
3.1.11
size of the sample
n
number of items in the sample
[SOURCE: ISO 7574-1:1985, 3.11].

3.1.12
arithmetic mean of a batch
arithmetic mean of a population
µ
sum of the noise emission values in a batch (or in a population) divided by the size of the
batch (or of the population)
[SOURCE: ISO 7574-1:1985, 3.12, modified – The term "arithmetic mean of a population"
has been explicitly added and the formula has been deleted.]
3.1.13
arithmetic mean of a sample
L
sum of the measured values, L , in a sample divided by the size of the sample
i
Note 1 to entry: The arithmetic mean value of the sample, is used as an estimator of the mean value of a batch
L
(or of a population), µ.
[SOURCE: ISO 7574-1:1985, 3.13, modified – The formula has been deleted and the
explanation has been transferred to Note 1 to entry.]
3.1.14
standard deviation of a batch
standard deviation of a population
σ
standard deviation of the noise emission values of the batch (or of the population) of the size
N is given by the equation
[SOURCE: ISO 7574-1:1985, 3.14, modified – The phrase "of size N is given by the equation"
and the related formula have been deleted.]
3.1.15
standard deviation of a sample
s
standard deviation of the sample is given by the equation

standard deviation of the noise emission values of the sample
Note 1 to entry: The standard deviation of the sample, s, is used as an estimator of the standard deviation of a
batch (or of a population), σ.
[SOURCE: ISO 7574-1:1985, 3.15, modified – Phrase "of the noise emission" has been added,
formula has been deleted and the explanation has been transferred to Note 1 to entry.]

– 10 – IEC 60704-3:2019 RLV © IEC 2019
3.1.16
standard deviation of repeatability
σ
r
standard deviation of noise emission values obtained under repeatability conditions, that is
the repeated application of the same noise emission measurement method on the same noise
source within a short interval of time under the same conditions (same laboratory, same
operator, same measuring equipment)
Note 1 to entry: Values for the standard deviation of repeatability, σ , obtained in practice, are given in Annex A.
r
[SOURCE: ISO 7574-1:1985, 3.16, modified – The phrase "same apparatus" has been
replaced by "same measurement equipment", reference to ISO 5725 has been deleted and
Note 1 to entry has been added.]
3.1.17
standard deviation of reproducibility
σ
R
standard deviation of noise emission values obtained under reproducibility conditions, that is
the repeated application of the same noise emission measurement method on the same noise
source at different times and under different conditions (different laboratory, different operator,
different measuring apparatus)
Note 1 to entry: The standard deviation of reproducibility includes therefore the standard deviation of repeatability
(see 3.1.16).
Note 2 to entry: Estimates of the standard deviation of reproducibility, σ , obtained in practice, are given in
R
Annex A.
[SOURCE: ISO 7574-1:1985, 3.17, modified – The reference to ISO 5725 has been deleted,
the second sentence has been transferred to Note 1 to entry and Note 2 to entry has been
added.]
3.1.18
standard deviation of production
σ
p
standard deviation of noise emission values obtained on different appliances from batches of
the same category (family), using the same noise emission measurement method under
repeatability conditions (same laboratory, same operator, same measuring apparatus)
Note 1 to entry: Estimates of the standard deviation of production, σ , obtained in practice, are given in Annex A.
P
[SOURCE: ISO 7574-1:1985, 3.18, modified – Phrase at the beginning has been replaced by
"of noise emission values obtained on different appliances from batches of the same category
(family)", the note has been deleted and Note 1 to entry has been added.]
3.1.19
total standard deviation
σ
t
square root of the sum of the squares of the standard deviation of reproducibility (see 3.1.17)
and of the standard deviation of production (see 3.1.18)

Note 1 to entry: Estimates of the total standard deviation, σ , obtained in practice are given in Annex A.
t
[SOURCE: ISO 7574-1:1985, 3.19, modified – The formula has been deleted and Note 1 to
entry has been added.]
3.1.20
reference standard deviation
σ
M
total standard deviation specified and fixed for the family of appliances under consideration
which is considered to be typical for batches from this family
Note 1 to entry: The use of a fixed σ for each category of appliances enables the application of a statistical
M
method to deal with small sample sizes.
Note 2 to entry: Values of the reference standard deviation, σ , fixed for the various categories of household
M
appliances (obtained from practical investigations) are given in Annex A.
[SOURCE: ISO 7574-1:1985, 3.20, modified – The words "and fixed" have been added,
"machines" has been replaced by "appliances", first sentence of note has been transferred to
a Note 1 of entry, remaining part of the note has been deleted and Note 2 to entry has been
added.]
3.1.21
single sampling
type of sampling which consists in taking only one sample from the batch
Note 1 to entry: See ISO 3534-1:19932006.
[SOURCE: ISO 7574-1:1985, 3.21, modified – Reference to ISO 3534-1 has been transferred
to Note 1 to entry.]
3.1.22
inspection by variables
method which consists in measuring a quantitative characteristic for each item of a population
or of a sample taken from this population
Note 1 to entry: The quantitative characteristic is the noise emission quantity.
Note 2 to entry: See ISO 3534-1:19932006.
[SOURCE: ISO 7574-1:1985, 3.24, modified – Second sentence has been transferred to Note
1 to entry, reference to ISO 3534-1 has been transferred to a Note 2 to entry and notes 1 and
2 have been deleted.]
3.1.23
probability of acceptance
P
a
probability that a batch of given quality (expressed by its proportion p of noise emission
values exceeding the labeled declared value) will be accepted by a given sampling plan
Note 1 to entry: (1–P ) is called "probability of rejection". If (1–P ) has the fixed value α (see 3.1.25), this is called
a a
the "producer's risk". If P has the fixed value β (see 3.1.26), this is called the "consumer's risk".
a
Note 2 to entry: See ISO 3534-1:19932006.
[SOURCE: ISO 7574-1:1985, 3.20 3.25, modified – Word "labelled" has been replaced by
"declared", the note has been transferred to Note 1 of entry and ISO 3534-1 has been
transferred to Note 2 to entry.]
3.1.24
operating characteristic curve
OC
curve showing, for a given sampling plan, the probability of acceptance P of a batch as a
a
function of its proportion p of noise emission values exceeding the declared values
Note 1 to entry: The operating characteristic curve is fully determined by two specified points [for example, the
producer's risk point (see 3.1.25) and the consumer's risk point (see 3.1.26)) or by one point (for example, the
producer's risk point) and the sample size n.
Note 2 to entry: See ISO 3534-1:19932006.
[SOURCE: ISO 7574-1:1985, 3.26, modified – The note has been transferred to Note1 to
entry and reference to ISO 3534-1 is made in Note 2 to entry.]

– 12 – IEC 60704-3:2019 RLV © IEC 2019
3.1.25
producer's risk point
point on the operating characteristic curve corresponding to a predetermined and usually low
probability of rejection α
Note 1 to entry: This probability of rejection is called the "producer's risk".
Note 2 to entry: The corresponding quality level is the proportion p of noise emission values of the batch
1–α
exceeding the declared value. For a continuous production, the proportion p would be approximately equal to
1–α
the acceptable quality level (AQL).
Note 3 to entry: See ISO 3534-1:19932006.
[SOURCE: ISO 7574-1:1985, 3.27, modified – The last sentence has been transferred to Note
1 to entry, the explanation has been transferred to Note 2 to entry, NOTE 1 has been deleted,
NOTE 2 has been added to Note 2 to entry and reference to ISO 3534-1 is made in Note 3 to
entry.]
3.1.26
consumer's risk point
point on the operating characteristic curve corresponding to a predetermined and usually low
probability of acceptance β
Note 1 to entry: This probability of acceptance is then called the "consumer's risk".
Note 2 to entry: See ISO 3534-1:2006.
[SOURCE: ISO 7574-1:1985, 3.28, modified – The second sentence has been transferred to
Note 1 to entry, the third sentence has been deleted and reference to ISO 3534-1 is made in
Note 2 to entry.]
3.2 Calculations
For the purposes of this document, the following calculation formulas apply:
3.2.1
sound power level
L
W
W
L 10⋅lg
dB
W
W
where W is the sound power of a source and W0 is the reference sound power, 1 pW
−12
(10 W).
Note 1 to entry: See 3.1.1.
3.2.2
arithmetic mean of a batch (or of a population)
µ
N
µ = L
i
∑
N
i=1
where N and L are defined in 3.1.9 and 3.1.4, respectively.
i
Note 1 to entry: See 3.1.12.
3.2.3
arithmetic mean of a sample
L
n
LL=
∑ i
n
i=1
where n and L are defined in 3.1.11 and 3.1.4., respectively.
i
=
Note 1 to entry: See 3.1.13.
3.2.4
standard deviation of a batch (or of a population)
σ
N
σµ(L− )
i
∑
N
i=1
where N, µ and L are defined in 3.1.9, 3.1.12 and 3.1.4, respectively.
i
Note 1 to entry: See 3.1.14.
3.2.5
standard deviation of a sample
s
N
s LL−
( )
i
∑
n −1
i=1
where n, L , and L are defined in 3.1.11, 3.1.13 and 3.1.4, respectively.
i
Note 1 to entry: See 3.1.15.
3.2.6
total standard deviation
σ
t
σ σσ+
t Rp
where σ and σ are defined in 3.1.17 and 3.1.18, respectively.
R p
Note 1 to entry: See 3.1.19.
4 General
4.1 Test method
All the measurements shall be performed according to IEC 60704 by a testing laboratory that
shall have appropriate test facilities and trained staff.
4.2 Values and symbols
In this document, the following values apply:
n (see 3.1.11) = 3
1–P = α (see 3.1.23) = 5 %, 1–α = 95 %
a
(see 3.1.25) = 6,5 %
p
1–α
U , U and U are values depending on the probability of acceptance P or 1–α
a
Pa 1–α q
(quantile of the standardized distribution) (see Figure 1)
U is selected by the labeller

Pa
U = 1,645
1–α
U = 1,514
q
=
=
=
– 14 – IEC 60704-3:2019 RLV © IEC 2019
U , U , U
P , 1–α, q
Pa 1–α q
a
99,9  % 3,091
99,75 % 2,807
99,50 % 2,576
P
a
99,25 % 2,433
1–α
99,00 % 2,327
q
97,50 % 1,960
U
95,00 % 1,645
93,50 % 1,514
92,50 % 1,440
90,00 % 1,282
75,00 % 0,674
50,00 % 0,000
IEC
Figure 1 – Quantile of the standardized distribution
4.3 Reference standard deviation
Table A.1 states fixed values for the reference standard deviation σ .
M
5 Verification of declared noise emission values
5.1 Basis of the procedure
The procedure for checking declared noise emission values of appliances coming in series or
batches from quantity production is for simplicity based on the "σ-method" with a fixed value
of reference standard deviation, σ , for each of the various categories of household
M
appliances (see Annex A), with single sampling of a very small size, and the (in practice not
fully correct) assumption that the noise emission values of a series or a batch will follow a
normal distribution.
Verifying compliance of the batch with the declared value is based on the following
assumptions:
– the noise emission values of the batch approximate to a normal distribution, characterized
by the mean value µ and the specified reference standard deviation σ ;
M
– the rejection probability for a batch is equal to a specified value α if the declared value L
c
is
is chosen so that the proportion of noise emission values of the batch exceeding L
c
equal to the specified value p .
1–α
If the batch and the declared value, L , conform with the values α = 5 % and p = 6,5 %, the
c 1–α
sampling inspection procedures are set in such a way that the batch will be accepted with the
probability of 1–α = 95 % and the mean value will be expected to lie approximately 1,5 σ
M
below the declared value.
NOTE The procedure for verifying declared noise emission values does not deal with the consequences to be
drawn if the declared value is not verified confirmed for a series or a batch of appliances.
5.2 Verification procedure
Take at random a sample of the size n = 3 (fixed by this document for verification purposes)
from the series or the batch under consideration.
Measure for each of the items the noise emission value L (i = 1, 2, 3) and determine the
i
arithmetic mean of these values L from

in accordance with 3.2.3.
Determine the value
A L−⋅k σ
cM
where k is the acceptability constant calculated from the formula (see ISO 7574-4).
u
1−α
k=u−=0,564
q
n
u and u represent the quantiles of the reduced standardized distribution for the values q =
q 1–α
1–p = 93,5 % and 1–α = 95 % respectively values, fixed by this document for verification
1–α
purposes.
If L ≤ A, the declared value is confirmed as verified for the series or the batch.
If L > A, the declared value is not confirmed as verified for the series or the batch.
For examples, see Annex B.
6 Determination of noise emission values for declaration
6.1 Basis of the procedure
A labeller who wants to define the risk of rejection (or probability of acceptance) by himself,
(possibly at a lower risk than 5 % as stated in Clause 5), and who has determined accurately
for his production a the total standard deviation for production, deviating from the reference
standard deviation fixed for the category of appliances under consideration, may calculate a
declared value L .
c
6.2 Determination procedure
Choose u .
Pa
Determine:
– the arithmetic mean of production µ;
– the value of the total standard deviation σ .
t
Calculate L from the following formula:
c
u
Pa
Lk= µσ+ ⋅ + σ
c Mt
n
which reads as, taking into account the values of the different parameters fixed by this
document for verification purposes:
Lu=µσ+⋅0,564 +⋅0,577 ⋅σ
c M Pa t
For examples, see Annex C.
6.3 Presentation of noise emission values
The declared values shall be expressed as clearly as possible in order to provide the
prospective user (buyer) with the correct information. In particular, it shall be emphasized that
sound power levels, which shall not be confused with sound pressure values, are used for
declaring noise emission values.
When noise emission values are declared in accordance with this document, it shall be clear
that they are expressed as an A-weighted sound power level in decibels (re 1 pW) and
indicate an upper statistical value below which a large proportion of the noise emission values
of the considered batch lies (it is not a mean value).
The value of L has to shall be rounded to the nearest decibel.
c
=
– 16 – IEC 60704-3:2019 RLV © IEC 2019
Annex A
(normative)
Noise emission of household appliances – Standard deviations
In Table A.1 estimated and fixed values are compiled for the In general, the following
standard deviation values are given in the parts of IEC 60704-2:
– standard deviation of repeatability σ ;
r
– standard deviation of reproducibility σ ;
R
– standard deviation of production σ ;
P
– total standard deviation σ ;
t
– reference standard deviation σ
M
The values are expressed in decibels.
For other appliance categories, values for the standard deviations are given in Table A.1.
These values, with the exception of the standard deviation of production σ , have been
P
determined for the most interesting categories of household appliances, relative to their noise
emission, during practical investigations carried out by a number of experienced industrial
laboratories. The values of the standard deviation of production σ are for guidance only.
P
Table A.1 – Standard deviation
Standard deviation
dB
Appliance category
σ σ σ σ σ
r R p t M
Vacuum cleaners 0,3 0,8 0,5 – 1,0 0,9 – 1,3 1,5
Shavers 0,4 0,8 0,7 to 1,3 1,1 to 1,5 1,5
Hair dryers 0,4 0,8 0,5 to 1,3 0,9 to 1,5 1,5
Hair clippers 0,4 1,0 0,8 to 1,2 1,3 to 1,6 1,5
Fan heaters 0,4 1,0 0,3 to 1,1 1,0 to 1,6 1,5
Storage heaters 0,4 1,0 0,7 – 1,1 1,2 – 1,5 2,0
Range hoods 0,4 1,0 1,5 – 1,7 1,8 – 2,0 2,0
Kitchen machines 0,5 1,0 0,9 to 1,5 1,4 to 1,8 2,0
Dishwashers 0,5 0,8 1,0 – 1,5 1.3 – 1,7 2,0
Spin extractors 0,5 1,0 1,0 – 1,2 1,4 – 1,6 2,0
Tumble dryers 0,4 0,8 0,7 – 1,0 1,1 – 1,3 1,5
Washing machines 0,6 1,0 1,0 – 2,2 1,4 – 2,4 2,5
Refrigerators 0,4 0,7 0,7 – 1,5 1,0 – 1,7 2,0
Freezers 0,4 0,7 1,0 – 2,0 1,2 – 2,1 2,5
Fans 0,4 1,0 0,5 – 1,0 1,1 – 1,4 1,5
Ovens 0,4 1,0 1,0 – 1,7 1,4 – 2,0 2,0

When a part 2 specifies standard deviations, these values shall supersede the values given
above in Table A.1.
In Table A.1, the values of standard deviations of production σ are informative and not
P
normative.
Annex B
(informative)
Verification of noise emission values – Examples
B.1 Example 1
A series of vacuum cleaners, manufacturer A, type X is labeled declared with:
L = 77 dB(A), re 1 pW
c
For checking For verification, a sample of n = 3 is investigated with the result:
L
L = 75,5 dB(A); L = 74,5 dB(A); L = 76,1 dB(A); mean value = 75,4 dB(A)
1 2 3
with the given L = 77 dB(A) and the fixed value σ = 1,5 dB for vacuum cleaners and
c M
k = 0,564:
A L−⋅k σ = 76,2 dB(A)
cM
L
Result: = 75,4 dB(A) < A = 76,2 dB(A) – the declared value is confirmed.
B.2 Example 2
A series of vacuum cleaners, manufacturer B, type Y is labeled declared with:
L = 79 dB(A), re 1 pW
c
For checking For verification, a sample of n = 3 is investigated with the result:
L = 78,7 dB(A); L = 79,0 dB(A) and L = 78,5 dB(A); mean value L = 78,7 dB(A)
1 2 3
with the given L = 79 dB(A) and the fixed value σ = 1,5 dB for vacuum cleaners
c M
and k = 0,564:
A L−⋅k σ = 78,2 dB(A)
cM
Result: L = 78,7 dB(A) > A = 78,2 dB(A) – the declared value is not confirmed.
NOTE The declared value should be changed to L = 80 dB(A) to pass this verification test.
c
=
=
– 18 – IEC 60704-3:2019 RLV © IEC 2019
Annex C
(informative)
Determination of noise emission values – Examples
C.1 Example 1
Table C.1 gives the results of the calculated and rounded declared values L , the real mean µ
c
and µ + 1,5 σ (q = 93,5 %) as a function of arbitrarily chosen values for the total standard
t
deviation σ and arbitrarily chosen values for the probability of acceptance P under the
t a
following conditions:
– for the production of the labeller:
• mean value of the production µ = 70,0 dB(A);
• three arbitrarily chosen values of total standard deviation σ = 1,0 dB or 2,0 dB or
t
3,0 dB;
• three arbitrarily chosen values for probability of acceptance P (or risk of
a
):
rejection 1 − P
a
P = 99,9 % or 99 % or 95 %.
a
Table C.1 – Calculated noise emission values as a function of the total standard
deviation σ and the probability of acceptance P as assumed by the labeller
t a
Total standard deviation
1,0 (< σ ) 2,0 (= σ ) 3,0 (> σ )
M M M
σ in dB
t
Real mean value
70,0 70,0 70,0
µ in dB (re 1 pW(A))
µ + 1,5 σ in dB(A)
t
71,5 73,0 74,5
(q = 93,5 %)
Probability of acceptance
99,9 99 95 99,9 99 95 99,9 99 95
P in %
a
Calculated declared value
73,0 72,5 72,0 74,7 73,8 73,0 76,5 75,1 74,0
L in dB(A)
c
Rounded declared value
73 73 72 75 74 73 77 75 74
L in dB(A)
c
C.2 Example 2
For a new model of vacuum cleaner, a pilot production of 9 items has shown the
following 9 noise values:
L = 75,2; 75,5; 75,9; 76,1; 76,2; 76,3; 76,3; 76,6; 76,8.
i
L = 75,2 dB(A); L = 75,5 dB(A); L = 75,9 dB(A); L = 76,1 dB(A); L = 76,2 dB(A);
1 2 3 4 5
L = 76,3 dB(A); L = 76,3 dB(A); L = 76,6 dB(A) and L = 76,8 dB(A).
6 7 8 9
From these values, L = 76,1 dB(A) and σ = 0,48 dB are calculated.
P
From these tests determining the standard deviation of reproducibility, carried out at a number
of experienced laboratories, σ = 0,8 dB has been found.
R
For these data, the total standard deviation will be:
σ σσ+ = 0,93 dB
t Rp
The value to be declared will be found from the following equation (see Clause 6):
u
Pa
Lk= µσ+ ⋅ + σ
c Mt
n
taking into account the data for the verification procedure with
n = 3, k = 0,564 (α = 5 %; q = 93,5 %), σ = 1,5 dB.
M
The labeller will calculate the following values to be declared if he chooses a risk of rejection
of:
0,1 % with u = 3,091
Pa
3,091
L (76,1+ 0,564⋅+1,5 0,93) dB(A) = 78,6 dB(A) 79 dB(A), re 1 pW
≈
c
1 % with u = 2,327
Pa
2,327
L (76,1+ 0,564⋅+1,5 0,93) dB(A) = 78,2 dB(A) ≈ 78 dB(A), re 1 pW
c
5 % with u = 1,645
Pa
1,645
L (76,1+ 0,564⋅+1,5 0,93)
dB(A) = 77,8 dB(A) ≈ 78 dB(A), re 1 pW
c
C.3 Example 3
For a series of a vacuum cleaner model the mean value and the total standard deviation have
been determined to be
µ = L = 76,1 dB(A) and σ = 1,7 dB.
t
Acceptable values to be declared will be found in accordance with Clause 6, with:
n = 3, k = 0,564 (α = 5 %; q = 93,5 %), σ = 1,5 dB,
M
if the labeller chooses the risk of rejection of correctly labeled declared samples:

0,1 % with u = 3,091
Pa
3,091
L (76,1+ 0,564⋅+1,5 1,7) dB(A) = 80,0 dB(A) ≈ 80 dB(A), re 1 pW
c
1 % with u = 2,327
Pa
2,327
L (76,1+ 0,564⋅+1,5 1,7)
dB(A) = 79,2 dB(A) ≈ 79 dB(A), re 1 pW
c
=
=
=
=
=
=
– 20 – IEC 60704-3:2019 RLV © IEC 2019
5 % with u = 1,645
Pa
1,645
L (76,1+ 0,564⋅+1,5 1,7) dB(A) = 78,6 dB(A) ≈ 79 dB(A), re 1 pW
c
=
Bibliography
ISO 3951-1:2005, Sampling procedures for inspection by variables – Part 1: Specification for
single sampling plans indexed by acceptance quality limit (AQL) for lot-by-lot inspection for a
single quality characteristic and a single AQL
ISO 4871:1996, Acoustics – Declaration and verification of noise emission values of
machinery and equipm
...

IEC 60704-3 ®
Edition 3.0 2019-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Household and similar electrical appliances – Test code for the determination
of airborne acoustical noise –
Part 3: Procedure for determining and verifying declared noise emission values

Appareils électrodomestiques et analogues – Code d'essai pour la détermination
du bruit aérien –
Partie 3: Méthode de détermination et de vérification des valeurs déclarées
d'émission sonore
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IEC 60704-3 ®
Edition 3.0 2019-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Household and similar electrical appliances – Test code for the determination

of airborne acoustical noise –

Part 3: Procedure for determining and verifying declared noise emission values

Appareils électrodomestiques et analogues – Code d'essai pour la

détermination du bruit aérien –

Partie 3: Méthode de détermination et de vérification des valeurs déclarées

d'émission sonore
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.140.20; 97.030 ISBN 978-2-8322-6975-6

– 2 – IEC 60704-3:2019 © IEC 2019
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and calculations . 6
3.1 Terms and definitions . 6
3.2 Calculations . 11
4 General . 12
4.1 Test method . 12
4.2 Values and symbols . 12
4.3 Reference standard deviation . 13
5 Verification of declared noise emission values . 13
5.1 Basis of the procedure . 13
5.2 Verification procedure . 14
6 Determination of noise emission values for declaration . 14
6.1 Basis of the procedure . 14
6.2 Determination procedure . 14
6.3 Presentation of noise emission values . 14
Annex A (normative) Noise emission of household appliances – Standard deviations . 16
Annex B (informative) Verification of noise emission values – Examples . 17
B.1 Example 1 . 17
B.2 Example 2 . 17
Annex C (informative) Determination of noise emission values – Examples . 18
C.1 Example 1 . 18
C.2 Example 2 . 18
C.3 Example 3 . 19
Bibliography . 20

Figure 1 – Quantile of the standardized distribution . 13

Table A.1 – Standard deviation . 16
Table C.1 – Calculated noise emission values as a function of the total standard
deviation σ and the probability of acceptance P as assumed by the labeller . 18
t a
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
TEST CODE FOR THE DETERMINATION OF AIRBORNE
ACOUSTICAL NOISE –
Part 3: Procedure for determining and verifying
declared noise emission values

FOREWORD
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International Standard IEC 60704-3 has been prepared by IEC technical committee 59:
Performance of household electrical appliances.
IEC 60704-1:2010 has served as a basis for the elaboration of this standard.
This third edition cancels and replaces the second edition published in 2006. This edition
constitutes a technical revision. It includes the following significant technical changes with
respect to the previous edition:
a) in Annex A, standard deviations that are now specified for various appliance categories in
the parts of IEC 60704-2 have been excluded from Table A.1;
b) furthermore, this edition makes reference to new standards and is implementing
ISO/IEC Directives, Part 2 in a more accurate manner.
Standard deviations specified in part 2 documents of the IEC 60704 series supersede the
values given in Table A.1.
– 4 – IEC 60704-3:2019 © IEC 2019
The text of this International Standard is based on the following documents:
CDV Report on voting
59/675/CDV 59/680A/RVC
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
This International Standard is to be used in conjunction with IEC 60704-1:2010 and the latest
edition of IEC 60704-2 (all parts).
A list of all parts in the IEC 60704 series, published under the general title Household and
similar electrical appliances – Test code for the determination of airborne acoustical noise,
can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.

INTRODUCTION
A comprehensive and correct declaration of noise emission is very helpful to enable the
potential buyer to make a good choice between appliances of the same category (serving for
the same purpose) of different makes or for different models.
In order to ensure a correct declaration of noise emission values, this part of IEC 60704
describes a simple method for verifying declared values and provides information for
determining the noise emission values.
Different countries are implementing different market surveillance strategies. This document
is not implementing a mandatory market surveillance strategy.

– 6 – IEC 60704-3:2019 © IEC 2019
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
TEST CODE FOR THE DETERMINATION OF AIRBORNE
ACOUSTICAL NOISE –
Part 3: Procedure for determining and verifying
declared noise emission values

1 Scope
This part of IEC 60704 describes procedures for determining and verifying the declared
values of the noise emitted by household and similar appliances.
It applies to all categories of household and similar electrical appliances covered by
IEC 60704-1 and all parts of IEC 60704-2, which include particular requirements for special
categories of appliances.
It applies to appliances being produced in quantity, such as in batches, series or lots, which
are manufactured to the same technical specification and characterized by the same declared
value of noise emission.
This part of IEC 60704:
– considers the term "declaration" to include all means for providing information on the noise
emission values to potential users (consumers) of the appliances; this includes labels,
brochures, advertisements, commercial and technical information papers, etc.;
– considers the declaration for appliances manufactured by mass production;
– specifies a simple statistical method for verifying the declared values by investigating a
sample of only three appliances.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC 60704-1:2010, Household and similar electrical appliances – Test code for the
determination of airborne acoustical noise – Part 1: General requirements
IEC 60704-2 (all parts), Household and similar electrical appliances – Test code for the
determination of airborne acoustical noise – Part 2: Particular requirements
ISO 3534-1:2006, Statistics – Vocabulary and symbols – Part 1: Probability and general
statistical terms
ISO 7574-4:1985, Acoustics – Statistical methods for determining and verifying stated noise
emission values of machinery and equipment – Part 4: Methods for stated values for batches
of machines
3 Terms, definitions and calculations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60704-1 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
sound power level
L
W
ten times the logarithm to the base 10 of the ratio of the sound power of a source to the
reference sound power, expressed in decibels
−12
Note 1 to entry: The reference sound power is 1 pW (10 W). The frequency weighting, or the midband
frequency of the frequency band used, is indicated in the symbol.
Note 2 to entry: For example, the A-weighted sound power level is L .
WA
3.1.2
A-weighted sound power level
L
WA
sound power level of an appliance, determined according to the appropriate requirements
specified in IEC 60704-1 and the relevant part of IEC 60704-2
Note 1 to entry: Henceforth, the subscript is left out for reasons of simplicity.
WA
3.1.3
noise emission value
single value of the noise emission quantity
3.1.4
measured value
L
i
noise emission value for an individual appliance determined in accordance with the
appropriate requirements of IEC 60704
3.1.5
family of appliances
category of appliances
appliances of similar design or type, or intended to perform the same functions
[SOURCE: ISO 7574-1:1985, 3.5, modified – The notes have been deleted, "category of
appliances" has been added as a preferred term, "machines" has been replaced by
"appliances" in the term and in the definition, and "or equipment" has been deleted from the
definition.]
3.1.6
declared value
L
c
value of the noise emission quantity which is rounded to the nearest decibel stated for all
appliances of a complete series of production or of a batch thereof, when the appliances are
new
Note 1 to entry: The declared value indicates the upper statistical value below which a specified large proportion
of noise emission values of the relevant batch lies. L depends on the specified verification procedure, which is
c
designed such that there is a probability of acceptance of 95 % for the batch, when no more than 6,5 % of all noise
emission values exceeds L , and if the specified reference standard deviations σ equals the actual total standard
c M
deviation σ .
t
[SOURCE: ISO 7574-1:1985, 3.6, modified – The term "stated value; labelled value" has been
replaced by "declared value"; the first sentence has been rephrased to "which is rounded to
the nearest decibel stated for all appliances of a complete series of production or of a batch
thereof" and "when the appliances are new" has been added; the second sentence has been
deleted; the fact "are new" is integrated in first sentence and notes 1 and 2 have been
replaced by a Note 1 to entry.]

– 8 – IEC 60704-3:2019 © IEC 2019
3.1.7
declaration
statement of the declared value, L , which is included in brochures, advertisements, product
c
or commercial literature and/or affixed to an appliance or part thereof for providing information
on the noise emission values to potential users (buyers, consumers) of the appliance
Note 1 to entry: The term "labeller" is used in this document for a person making declarations.
[SOURCE: ISO 7574-1:1985, 3.7, modified – The term "label" has been replaced by
"declaration", "brochures, advertisements, or commercial literature" have been added, the
phrase after "and/or affixed" has been replaced by "to an appliance or part thereof for
providing information on the noise emission values to potential users (buyers, consumers) of
the appliance" and Note 1 to entry has been added.]
3.1.8
batch of appliances
group of the same family produced in quantity, manufactured to the same technical
specifications and characterized by the same declared value, L
c
Note 1 to entry: A batch may be either an entire production series or a portion thereof.
[SOURCE: ISO 7574-1:1985, 3.8, modified – The term "batch (lot) of machines" has been
replaced by "batch of appliances" and the note has been transferred into Note 1 to entry.]
3.1.9
size of the batch
size of the population
N
number of items (appliances in the batch or noise emission values in the population) of the
batch (or of the population)
[SOURCE: ISO 7574-1:1985, 3.9, modified – The term "size of the population" has been
explicitely added as a preferred term, word "machines" is replaced by "appliances" and
phrase "of the batch (or of the population)" is added.]
3.1.10
sample
one or more appliances (or measured values) randomly selected from a lot (or population)
[SOURCE: ISO 7574-1:1985, 3.10, modified – "Machines" is replaced by "appliances".]
3.1.11
size of the sample
n
number of items in the sample
[SOURCE: ISO 7574-1:1985, 3.11].
3.1.12
arithmetic mean of a batch
arithmetic mean of a population
µ
sum of the noise emission values in a batch (or in a population) divided by the size of the
batch (or of the population)
[SOURCE: ISO 7574-1:1985, 3.12, modified – The term "arithmetic mean of a population"
has been explicitly added and the formula has been deleted.]
3.1.13
arithmetic mean of a sample
L
sum of the measured values, L , in a sample divided by the size of the sample
i
Note 1 to entry: The arithmetic mean value of the sample, is used as an estimator of the mean value of a batch
L
(or of a population), µ.
[SOURCE: ISO 7574-1:1985, 3.13, modified – The formula has been deleted and the
explanation has been transferred to Note 1 to entry.]
3.1.14
standard deviation of a batch
standard deviation of a population
σ
standard deviation of the noise emission values of the batch (or of the population)
[SOURCE: ISO 7574-1:1985, 3.14, modified – The phrase "of size N is given by the equation"
and the related formula have been deleted.]
3.1.15
standard deviation of a sample
s
standard deviation of the noise emission values of the sample
Note 1 to entry: The standard deviation of the sample, s, is used as an estimator of the standard deviation of a
batch (or of a population), σ.
[SOURCE: ISO 7574-1:1985, 3.15, modified – Phrase "of the noise emission" has been added,
formula has been deleted and the explanation has been transferred to Note 1 to entry.]
3.1.16
standard deviation of repeatability
σ
r
standard deviation of noise emission values obtained under repeatability conditions, that is
the repeated application of the same noise emission measurement method on the same noise
source within a short interval of time under the same conditions (same laboratory, same
operator, same measuring equipment)
Note 1 to entry: Values for the standard deviation of repeatability, σ , obtained in practice, are given in Annex A.
r
[SOURCE: ISO 7574-1:1985, 3.16, modified – The phrase "same apparatus" has been
replaced by "same measurement equipment", reference to ISO 5725 has been deleted and
Note 1 to entry has been added.]
3.1.17
standard deviation of reproducibility
σ
R
standard deviation of noise emission values obtained under reproducibility conditions, that is
the repeated application of the same noise emission measurement method on the same noise
source at different times and under different conditions (different laboratory, different operator,
different measuring apparatus)
Note 1 to entry: The standard deviation of reproducibility includes the standard deviation of repeatability
(see 3.1.16).
Note 2 to entry: Estimates of the standard deviation of reproducibility, σ , obtained in practice, are given in
R
Annex A.
[SOURCE: ISO 7574-1:1985, 3.17, modified – The reference to ISO 5725 has been deleted,
the second sentence has been transferred to Note 1 to entry and Note 2 to entry has been
added.]
3.1.18
standard deviation of production
σ
p
standard deviation of noise emission values obtained on different appliances from batches of
the same category (family), using the same noise emission measurement method under
repeatability conditions (same laboratory, same operator, same measuring apparatus)

– 10 – IEC 60704-3:2019 © IEC 2019
Note 1 to entry: Estimates of the standard deviation of production, σ , obtained in practice, are given in Annex A.
P
[SOURCE: ISO 7574-1:1985, 3.18, modified – Phrase at the beginning has been replaced by
"of noise emission values obtained on different appliances from batches of the same category
(family)", the note has been deleted and Note 1 to entry has been added.]
3.1.19
total standard deviation
σ
t
square root of the sum of the squares of the standard deviation of reproducibility (see 3.1.17)
and of the standard deviation of production (see 3.1.18)
Note 1 to entry: Estimates of the total standard deviation, σ , obtained in practice are given in Annex A.
t
[SOURCE: ISO 7574-1:1985, 3.19, modified – The formula has been deleted and Note 1 to
entry has been added.]
3.1.20
reference standard deviation
σ
M
total standard deviation specified and fixed for the family of appliances under consideration
which is considered to be typical for batches from this family
Note 1 to entry: The use of a fixed σ for each category of appliances enables the application of a statistical
M
method to deal with small sample sizes.
Note 2 to entry: Values of the reference standard deviation, σ , fixed for the various categories of household
M
appliances (obtained from practical investigations) are given in Annex A.
[SOURCE: ISO 7574-1:1985, 3.20, modified – The words "and fixed" have been added,
"machines" has been replaced by "appliances", first sentence of note has been transferred to
a Note 1 of entry, remaining part of the note has been deleted and Note 2 to entry has been
added.]
3.1.21
single sampling
type of sampling which consists in taking only one sample from the batch
Note 1 to entry: See ISO 3534-1:2006.
[SOURCE: ISO 7574-1:1985, 3.21, modified – Reference to ISO 3534-1 has been transferred
to Note 1 to entry.]
3.1.22
inspection by variables
method which consists in measuring a quantitative characteristic for each item of a population
or of a sample taken from this population
Note 1 to entry: The quantitative characteristic is the noise emission quantity.
Note 2 to entry: See ISO 3534-1:2006.
[SOURCE: ISO 7574-1:1985, 3.24, modified – Second sentence has been transferred to Note
1 to entry, reference to ISO 3534-1 has been transferred to a Note 2 to entry and notes 1 and
2 have been deleted.]
3.1.23
probability of acceptance
P
a
probability that a batch of given quality (expressed by its proportion p of noise emission
values exceeding the declared value) will be accepted by a given sampling plan
Note 1 to entry: (1–P ) is called "probability of rejection". If (1–P ) has the fixed value α (see 3.1.25), this is called
a a
the "producer's risk". If P has the fixed value β (see 3.1.26), this is called the "consumer's risk".
a
Note 2 to entry: See ISO 3534-1:2006.

[SOURCE: ISO 7574-1:1985, 3.25, modified – Word "labelled" has been replaced by
"declared", the note has been transferred to Note 1 of entry and ISO 3534-1 has been
transferred to Note 2 to entry.]
3.1.24
operating characteristic curve
OC
curve showing, for a given sampling plan, the probability of acceptance P of a batch as a
a
function of its proportion p of noise emission values exceeding the declared values
Note 1 to entry: The operating characteristic curve is fully determined by two specified points [for example, the
producer's risk point (see 3.1.25) and the consumer's risk point (see 3.1.26)) or by one point (for example, the
producer's risk point) and the sample size n.
Note 2 to entry: See ISO 3534-1:2006.
[SOURCE: ISO 7574-1:1985, 3.26, modified – The note has been transferred to Note1 to
entry and reference to ISO 3534-1 is made in Note 2 to entry.]
3.1.25
producer's risk point
point on the operating characteristic curve corresponding to a predetermined and usually low
probability of rejection α
Note 1 to entry: This probability of rejection is called the "producer's risk".
Note 2 to entry: The corresponding quality level is the proportion p of noise emission values of the batch
1–α
exceeding the declared value. For a continuous production, the proportion p would be approximately equal to
1–α
the acceptable quality level (AQL).
Note 3 to entry: See ISO 3534-1:2006.
[SOURCE: ISO 7574-1:1985, 3.27, modified – The last sentence has been transferred to Note
1 to entry, the explanation has been transferred to Note 2 to entry, NOTE 1 has been deleted,
NOTE 2 has been added to Note 2 to entry and reference to ISO 3534-1 is made in Note 3 to
entry.]
3.1.26
consumer's risk point
point on the operating characteristic curve corresponding to a predetermined and usually low
probability of acceptance β
Note 1 to entry: This probability of acceptance is then called the "consumer's risk".
Note 2 to entry: See ISO 3534-1:2006.
[SOURCE: ISO 7574-1:1985, 3.28, modified – The second sentence has been transferred to
Note 1 to entry, the third sentence has been deleted and reference to ISO 3534-1 is made in
Note 2 to entry.]
3.2 Calculations
For the purposes of this document, the following calculation formulas apply:
3.2.1
sound power level
L
W
W
L 10⋅lg
dB
W
W
where W is the sound power of a source and W is the reference sound power, 1 pW
−12
(10 W).
Note 1 to entry: See 3.1.1.
=
– 12 – IEC 60704-3:2019 © IEC 2019
3.2.2
arithmetic mean of a batch (or of a population)
µ
N
µ = L
∑ i
N
i=1
where N and L are defined in 3.1.9 and 3.1.4, respectively.
i
Note 1 to entry: See 3.1.12.
3.2.3
arithmetic mean of a sample
L
n
LL=
i
∑
n
i=1
where n and L are defined in 3.1.11 and 3.1.4., respectively.
i
Note 1 to entry: See 3.1.13.
3.2.4
standard deviation of a batch (or of a population)
σ
N
σµL−
( )
i
∑
N
i=1
where N, µ and L are defined in 3.1.9, 3.1.12 and 3.1.4, respectively.
i
Note 1 to entry: See 3.1.14.
3.2.5
standard deviation of a sample
s
N
s LL−
( )
i
∑
n −1
i=1
where n, L , and L are defined in 3.1.11, 3.1.13 and 3.1.4, respectively.
i
Note 1 to entry: See 3.1.15.
3.2.6
total standard deviation
σ
t
σ σσ+
t Rp
where σ and σ are defined in 3.1.17 and 3.1.18, respectively.
R p
Note 1 to entry: See 3.1.19.
4 General
4.1 Test method
All the measurements shall be performed according to IEC 60704 by a testing laboratory that
shall have appropriate test facilities and trained staff.
4.2 Values and symbols
In this document, the following values apply:

=
=
=
n (see 3.1.11) = 3
1–P = α (see 3.1.23) = 5 %, 1–α = 95 %
a
p  (see 3.1.25) = 6,5 %
1–α
U , U and U are values depending on the probability of acceptance P or 1–α
a
Pa 1–α q
(quantile of the standardized distribution) (see Figure 1)
U is selected by the labeller

Pa
U = 1,645
1–α
U = 1,514
q
U , U , U
P , 1–α, q
Pa 1–α q
a
99,9  % 3,091
99,75 % 2,807
99,50 % 2,576
P
a
99,25 % 2,433
1–α
99,00 % 2,327
q
97,50 % 1,960
U 95,00 % 1,645
93,50 % 1,514
92,50 % 1,440
90,00 % 1,282
75,00 % 0,674
50,00 % 0,000
IEC
Figure 1 – Quantile of the standardized distribution
4.3 Reference standard deviation
Table A.1 states fixed values for the reference standard deviation σ .
M
5 Verification of declared noise emission values
5.1 Basis of the procedure
The procedure for checking declared noise emission values of appliances coming in series or
batches from quantity production is for simplicity based on the "σ-method" with a fixed value
of reference standard deviation, σ , for each of the various categories of household
M
appliances (see Annex A), with single sampling of a very small size, and the (in practice not
fully correct) assumption that the noise emission values of a series or a batch will follow a
normal distribution.
Verifying compliance of the batch with the declared value is based on the following
assumptions:
– the noise emission values of the batch approximate to a normal distribution, characterized
by the mean value µ and the specified reference standard deviation σ ;
M
– the rejection probability for a batch is equal to a specified value α if the declared value L
c
is chosen so that the proportion of noise emission values of the batch exceeding L is
c
equal to the specified value p .
1–α
If the batch and the declared value, L , conform with the values α = 5 % and p = 6,5 %, the
c 1–α
sampling inspection procedures are set in such a way that the batch will be accepted with the
probability of 1–α = 95 % and the mean value will be expected to lie approximately 1,5 σ
M
below the declared value.
NOTE The procedure for verifying declared noise emission values does not deal with the consequences to be
drawn if the declared value is not confirmed for a series or a batch of appliances.

– 14 – IEC 60704-3:2019 © IEC 2019
5.2 Verification procedure
Take at random a sample of the size n = 3 (fixed by this document for verification purposes)
from the series or the batch under consideration.
Measure for each of the items the noise emission value L (i = 1, 2, 3) and determine the
i
arithmetic mean of these values L in accordance with 3.2.3.
Determine the value
A L−⋅k σ
cM
where k is the acceptability constant calculated from the formula (see ISO 7574-4).
u
1−α
k=u−=0,564
q
n
u and u represent the quantiles of the reduced standardized distribution for the values q =
q 1–α
1–p = 93,5 % and 1–α = 95 % respectively, fixed by this document for verification
1–α
purposes.
If L ≤ A, the declared value is confirmed as verified for the series or the batch.
If > A, the declared value is not confirmed as verified for the series or the batch.
L
For examples, see Annex B.
6 Determination of noise emission values for declaration
6.1 Basis of the procedure
A labeller who wants to define the risk of rejection (or probability of acceptance) by himself, at
a lower risk than 5 % stated in Clause 5, and has determined accurately the total standard
deviation for production, deviating from the reference standard deviation fixed for the category
L .
of appliances under consideration, may calculate a declared value
c
6.2 Determination procedure
Choose u .
Pa
Determine:
– the arithmetic mean of production µ;
– the value of the total standard deviation σ .
t
Calculate L from the following formula:
c
u
Pa
Lk= µσ+ ⋅ + σ
c Mt
n
which reads as, taking into account the values of the different parameters fixed by this
document for verification purposes:
Lu=µσ+⋅0,564 +⋅0,577 ⋅σ
c M Pa t
For examples, see Annex C.
6.3 Presentation of noise emission values
The declared values shall be expressed as clearly as possible in order to provide the
prospective user (buyer) with the correct information. In particular, it shall be emphasized that

=
sound power levels, which shall not be confused with sound pressure values, are used for
declaring noise emission values.
When noise emission values are declared in accordance with this document, it shall be clear
that they are expressed as an A-weighted sound power level in decibels (re 1 pW) and
indicate an upper statistical value below which a large proportion of the noise emission values
of the considered batch lies (it is not a mean value).
The value of L shall be rounded to the nearest decibel.
c
– 16 – IEC 60704-3:2019 © IEC 2019
Annex A
(normative)
Noise emission of household appliances – Standard deviations
In general, the following standard deviation values are given in the parts of IEC 60704-2:
– standard deviation of repeatability σ ;
r
– standard deviation of reproducibility σ ;
R
– standard deviation of production σ ;
P
– total standard deviation σ ;
t
– reference standard deviation σ .
M
The values are expressed in decibels.
For other appliance categories, values for the standard deviations are given in Table A.1.
These values, with the exception of the standard deviation of production σ , have been
P
determined during practical investigations carried out by a number of experienced industrial
laboratories. The values of the standard deviation of production σ are for guidance only.
P
Table A.1 – Standard deviation
Standard deviation
dB
Appliance category
σ σ σ σ σ
r R p t M
Shavers 0,4 0,8 0,7 to 1,3 1,1 to 1,5 1,5
Hair dryers 0,4 0,8 0,5 to 1,3 0,9 to 1,5 1,5
Hair clippers 0,4 1,0 0,8 to 1,2 1,3 to 1,6 1,5
Fan heaters 0,4 1,0 0,3 to 1,1 1,0 to 1,6 1,5
Kitchen machines 0,5 1,0 0,9 to 1,5 1,4 to 1,8 2,0

Annex B
(informative)
Verification of noise emission values – Examples
B.1 Example 1
A series of vacuum cleaners, manufacturer A, type X is declared with:
L = 77 dB(A), re 1 pW
c
For verification, a sample of n = 3 is investigated with the result:
L = 75,5 dB(A); L = 74,5 dB(A); L = 76,1 dB(A); mean value L = 75,4 dB(A)
1 2 3
with the given L = 77 dB(A) and the fixed value σ = 1,5 dB for vacuum cleaners and
c M
k = 0,564:
A L−⋅k σ = 76,2 dB(A)
cM
Result: L = 75,4 dB(A) < A = 76,2 dB(A) – the declared value is confirmed.
B.2 Example 2
A series of vacuum cleaners, manufacturer B, type Y is declared with:
L = 79 dB(A), re 1 pW
c
For verification, a sample of n = 3 is investigated with the result:
L = 78,7 dB(A); L = 79,0 dB(A) and L = 78,5 dB(A); mean value L = 78,7 dB(A)
1 2 3
with the given L = 79 dB(A) and the fixed value σ = 1,5 dB for vacuum cleaners and
c M
k = 0,564:
A L−⋅k σ = 78,2 dB(A)
cM
Result: L = 78,7 dB(A) > A = 78,2 dB(A) – the declared value is not confirmed.
The declared value should be changed to L = 80 dB(A) to pass this verification test.
c
=
=
– 18 – IEC 60704-3:2019 © IEC 2019
Annex C
(informative)
Determination of noise emission values – Examples
C.1 Example 1
Table C.1 gives the results of the calculated and rounded declared values L , the real mean µ
c
and µ + 1,5 σ (q = 93,5 %) as a function of arbitrarily chosen values for the total standard
t
deviation σ and arbitrarily chosen values for the probability of acceptance P under the
t a
following conditions:
– for the production of the labeller:
• mean value of the production µ = 70,0 dB(A);
• three arbitrarily chosen values of total standard deviation σ = 1,0 dB or 2,0 dB or
t
3,0 dB;
• three arbitrarily chosen values for probability of acceptance P (or risk of
a
):
rejection 1 − P
a
P = 99,9 % or 99 % or 95 %.
a
Table C.1 – Calculated noise emission values as a function of the total standard
deviation σ and the probability of acceptance P as assumed by the labeller
t a
Total standard deviation
1,0 (< σ ) 2,0 (= σ ) 3,0 (> σ )
M M M
σ in dB
t
Real mean value
70,0 70,0 70,0
µ in dB (re 1 pW(A))
µ + 1,5 σ in dB(A)
t
71,5 73,0 74,5
(q = 93,5 %)
Probability of acceptance
99,9 99 95 99,9 99 95 99,9 99 95
P in %
a
Calculated declared value
73,0 72,5 72,0 74,7 73,8 73,0 76,5 75,1 74,0
L in dB(A)
c
Rounded declared value
73 73 72 75 74 73 77 75 74
L in dB(A)
c
C.2 Example 2
For a new model of vacuum cleaner, a pilot production of 9 items has shown the
following 9 noise values:
= 75,2 dB(A); L = 75,5 dB(A); L = 75,9 dB(A); L = 76,1 dB(A); L = 76,2 dB(A);
L
1 2 3 4 5
L = 76,3 dB(A); L = 76,3 dB(A); L = 76,6 dB(A) and L = 76,8 dB(A).
6 7 8 9
From these values, L = 76,1 dB(A) and σ = 0,48 dB are calculated.
P
From these tests determining the standard deviation of reproducibility, carried out at a number
of experienced laboratories, σ = 0,8 dB has been found.
R
For these data, the total standard deviation will be:

σ σσ+ = 0,93 dB
t Rp
The value to be declared will be found from the following equation (see Clause 6):
u
Pa
Lk= µσ+ ⋅ + σ
c Mt
n
taking into account the data for the verification procedure with
n = 3, k = 0,564 (α = 5 %; q = 93,5 %), σ = 1,5 dB.
M
The labeller will calculate the following values to be declared if he chooses a risk of rejection
of:
0,1 % with u = 3,091
Pa
3,091
L (76,1+ 0,564⋅+1,5 0,93) dB(A) = 78,6 dB(A) 79 dB(A), re 1 pW
≈
c
1 % with u = 2,327
Pa
2,327
L (76,1+ 0,564⋅+1,5 0,93) dB(A) = 78,2 dB(A) ≈ 78 dB(A), re 1 pW
c
5 % with u = 1,645
Pa
1,645
L (76,1+ 0,564⋅+1,5 0,93) dB(A) = 77,8 dB(A) ≈ 78 dB(A), re 1 pW
c
C.3 Example 3
For a series of a vacuum cleaner model the mean value and the total standard deviation have
been determined to be
µ = L = 76,1 dB(A) and σ = 1,7 dB.
t
Acceptable values to be declared will be found in accordance with Clause 6, with:
n = 3, k = 0,564 (α = 5 %; q = 93,5 %), σ = 1,5 dB,
M
if the labeller chooses th
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