🌿 Determination of occupational noise exposure — three measurement strategies, PN-EN ISO 9612
In short
The standard specifies a method for measuring workers’ noise exposure and a way of calculating the exposure level, describing THREE different measurement strategies together with methods for estimating the uncertainty of the result. The test is performed according to PN-EN ISO 9612:2025-11 (wersja angielska; wprowadza EN ISO 9612:2025 [IDT] oraz ISO 9612:2025 [IDT]); WHAT LABORATORIES DO WITH THESE THREE STRATEGIES (measurement on the scope database, reading of 23.09.2026): the standard is cited by 520 entries at 245 laboratories, and 491 entries at 237 laboratories cite it WITH A STRATEGY EXCLUSION — i.e. 94 % of the citations. Without any exclusion: 29 entries at 11 laboratories. The procedure comprises 7 steps; it is used for: Noise measurements at workplaces for the assessment of occupational exposure and the risk of hearing damage, Epidemiological studies of hearing damage and other adverse effects of noise, Setting priorities when planning noise control measures.
At a glance
- Standard: PN-EN ISO 9612:2025-11 (wersja angielska; wprowadza EN ISO 9612:2025 [IDT] oraz ISO 9612:2025 [IDT])
- Category: Environment
- Procedure steps: 7
- WHAT LABORATORIES DO WITH THESE THREE STRATEGIES (measurement on the scope database, reading of 23.09.2026): the standard is cited by 520 entries at 245 laboratories, and 491 entries at 237 laboratories cite it WITH A STRATEGY EXCLUSION — i.e. 94 % of the citations. Without any exclusion: 29 entries at 11 laboratories
- WHICH STRATEGIES ARE EXCLUDED (measurement repeated on 23.09.2026 after the rule was corrected): strategies 2 and 3 together — 402 entries / 193 laboratories; strategy 2 alone — 24 / 13; strategy 3 alone — 65 / 31; records with an exclusion but without a strategy number — ZERO; citations without any exclusion — 29 / 11. THE ASSIGNMENT RULE, because the whole distribution depends on it: we take the fragment from the word "strategi" [the stem of the Polish word for strategy] up to forty characters further on and look in IT for the digits 2 and 3; an entry goes into the category "2 and 3" when both stand in this fragment. CORRECTION: the previous wording gave 187 / 218 / 50 / 36, and these were numbers from a rule requiring the digit DIRECTLY after the word. The most frequent record in the scopes reads "z wyłączeniem metody obejmującej strategię 2 i 3 – punkt 10 i 11" [excluding the method covering strategies 2 and 3 – clauses 10 and 11] (48 times with an en dash, 45 with a hyphen), and the second most frequent — "strategię 2 – punkt 10 i strategię 3 – punkt 11" [strategy 2 – clause 10 and strategy 3 – clause 11] (26 and 22 times): when searching for the digit three, the pattern hit the two and dropped out, so entries with BOTH strategies landed in the category "2 alone".
- What this means for the client: a citation of "PN-EN ISO 9612" in an offer or in a test report does NOT say which strategy the measurement was performed with — and in the accreditation scopes nine out of ten entries are limited to some of the strategies of the standard. The strategy has to be checked in the scope of the laboratory, not in the number of the standard
Overview
HOW MANY LABORATORIES THE TAB WILL NOT SHOW (measurement of 23.09.2026). Matching works on the BEGINNING of the value of the reference-document field. 245 laboratories have this standard in their scope of accreditation, while the tab shows 189 — it will not show FIFTY-SIX. There are two causes and each needs a different repair: 46 laboratories have EXACTLY THIS FORM of the designation, only not at the beginning of the value ("POSITION"), and 10 wrote the standard in a DIFFERENT FORM — "PN-ISO 9612" without the EN element, "PN EN-ISO 9612" without the hyphen, "PN-ISO 9612:2025-11" ("FORM"). A FORM can be covered by the key; a POSITION cannot be covered at all. The most frequent form: "PN-N-01307:1994 PN-EN ISO 9612:2011 z wyłączeniem metody obejmującej strategię…" (excluding the method covering the strategy…). THE CAUSE LIES IN THE FIELD ITSELF, NOT IN CARELESSNESS: PN-N-01307 is a standard on the permissible values of noise, and 9612 one on the method of measurement — the laboratory enters them in the order in which the test proceeds. No key will repair this, because these records have no common beginning; a repair would require matching on content instead of on the beginning, and that is a change in the program with its own risk of excess. We give the figure here so that the reader knows the list is shorter than the actual state — just as with the IEC element in the 61000 family.
A CHANGE OF EDITION THAT MUST BE STATED AT THE OUTSET. Until 27 November 2025 the edition in force was PN-EN ISO 9612:2011 in the POLISH version. On that day it was withdrawn and superseded by PN-EN ISO 9612:2025-11, available in English only. The third element of the title also changed: it used to read "Engineering method", it now reads "Methodology". A laboratory whose documentation cites "PN-EN ISO 9612:2011" is citing a withdrawn document; a reference without a year does not settle which edition is meant. Both catalogue cards were retrieved on 15 September 2026 — the "Date of withdrawal" row on the 2011 edition gives 27-11-2025, and the "Superseded by" row points to the 2025-11 edition.
THE SCOPE FROM THE PKN CATALOGUE CARD, IN FULL: "This document specifies a method for measuring the exposure of workers to noise in the working environment and a method for calculating the noise exposure level. This document applies to A-weighted levels, but is also applicable to C-weighted levels. Three different measurement strategies are described. The method is applicable to detailed studies of noise exposure or to epidemiological studies of hearing damage or other adverse effects. The measurement process requires observation and analysis of the noise exposure conditions so that the quality of the measurements can be controlled. This document gives methods for estimating the uncertainty of the results. This document is not intended for the assessment of speech communication masking or for the assessment of infrasound, ultrasound and non-auditory effects of noise. It is not applicable to the measurement of ear exposure to noise when hearing protectors are worn. The results of measurements carried out in accordance with this document may provide useful information when setting priorities for noise control measures."
THREE EXCLUSIONS THAT SETTLE DISPUTES. The scope expressly excludes three things, and each of them is a frequent source of misunderstanding with the client. First: the standard is NOT for assessing the masking of speech communication — the question "can people make themselves understood in this hall" is not one this method answers. Second: it does not cover infrasound, ultrasound or the non-auditory effects of noise — ultrasonic noise has its own standard and its own limit values in Poland. Third, and this is the most common error: it does NOT apply to measuring ear exposure when hearing protectors are worn. The level measured by this method describes the noise reaching the worker, not the noise under the protector; the attenuation of protectors is accounted for by a separate calculation under other documents.
THREE STRATEGIES — AND WHY THE CHOICE IS NOT INDIFFERENT. The standard does not impose a single way of measuring; it gives three strategies. They differ in what the measurement is organised around: the task performed by the worker, the job, or the whole work shift. The choice of strategy affects the number of measurements needed, the way the result is calculated, and the uncertainty. A report that does not state the strategy used does not allow the reader to reconstruct how the result came about — and with this standard that information ranks equally with the instrument used.
A-WEIGHTED AND C-WEIGHTED LEVELS. The scope says the document applies to A-weighted levels but "is also applicable" to C-weighted levels. The distinction matters in practice: the A-weighting curve corresponds to the sensitivity of the ear at typical levels and serves the assessment of the risk of hearing damage from long-term exposure; the C-weighting curve is flatter in the low-frequency range and is used with impulsive noise and in the selection of hearing protectors. A result given without stating the weighting curve is incomplete.
UNCERTAINTY IS PART OF THE METHOD, NOT AN APPENDIX. The scope lists methods for estimating the uncertainty of results as an element of the standard, not as a recommendation. With noise the uncertainty can be large — because the source of variability is not only the instrument but the variability of the work itself — and it can decide whether a result exceeds the limit value or not. A report without an uncertainty does not allow that assessment to be made.
WHAT WE DO NOT GIVE. We do not have the text of the standard — PKN supplies it for a fee (66 pages, TC 157, Physical Hazards in the Working Environment, ICS 13.140). We therefore DO NOT GIVE the names or descriptions of the three strategies, the calculation formulae, the required number of measurements or any uncertainty values. We know from the scope that there are three strategies and that the standard gives methods for estimating uncertainty — and that is the limit of what we may state without the text.
Method principle
Noise exposure is a quantity referred to time: what is measured is not "the loudness in the hall" but the dose of sound a worker receives during a shift. The measurement consists in recording sound levels under conditions of real work and calculating the exposure level from them, the way of organising the measurement being chosen from among the three strategies described in the standard. A condition of correctness is the observation and analysis of the exposure conditions — without establishing what the worker does and for how long, instrument readings alone do not give a result. An estimate of uncertainty, determined by the methods given in the standard, is attached to the outcome.
Applications
- Noise measurements at workplaces for the assessment of occupational exposure and the risk of hearing damage
- Epidemiological studies of hearing damage and other adverse effects of noise
- Setting priorities when planning noise control measures
- Accreditation of occupational hygiene laboratories in the field of physical agents
Key parameters
| Parameter | Value |
|---|---|
| WHAT LABORATORIES DO WITH THESE THREE STRATEGIES (measurement on the scope database, reading of 23.09.2026) | the standard is cited by 520 entries at 245 laboratories, and 491 entries at 237 laboratories cite it WITH A STRATEGY EXCLUSION — i.e. 94 % of the citations. Without any exclusion: 29 entries at 11 laboratories |
| WHICH STRATEGIES ARE EXCLUDED (measurement repeated on 23.09.2026 after the rule was corrected) | strategies 2 and 3 together — 402 entries / 193 laboratories; strategy 2 alone — 24 / 13; strategy 3 alone — 65 / 31; records with an exclusion but without a strategy number — ZERO; citations without any exclusion — 29 / 11. THE ASSIGNMENT RULE, because the whole distribution depends on it: we take the fragment from the word "strategi" [the stem of the Polish word for strategy] up to forty characters further on and look in IT for the digits 2 and 3; an entry goes into the category "2 and 3" when both stand in this fragment. CORRECTION: the previous wording gave 187 / 218 / 50 / 36, and these were numbers from a rule requiring the digit DIRECTLY after the word. The most frequent record in the scopes reads "z wyłączeniem metody obejmującej strategię 2 i 3 – punkt 10 i 11" [excluding the method covering strategies 2 and 3 – clauses 10 and 11] (48 times with an en dash, 45 with a hyphen), and the second most frequent — "strategię 2 – punkt 10 i strategię 3 – punkt 11" [strategy 2 – clause 10 and strategy 3 – clause 11] (26 and 22 times): when searching for the digit three, the pattern hit the two and dropped out, so entries with BOTH strategies landed in the category "2 alone". |
| What this means for the client | a citation of "PN-EN ISO 9612" in an offer or in a test report does NOT say which strategy the measurement was performed with — and in the accreditation scopes nine out of ten entries are limited to some of the strategies of the standard. The strategy has to be checked in the scope of the laboratory, not in the number of the standard |
| Where this number comes from — a note on the notation | in the scopes, exclusions of strategies are written with the FULL WORD "punkt" [clause] ("z wyłączeniem metody obejmującej strategię 3 – punkt 11" [excluding the method covering strategy 3 – clause 11]), not with the abbreviation "pkt" or "p.". A pattern searching for the two abbreviations misses this class entirely — for this standard there are 317 such entries, and in the whole scope database 541 (measurement 23.09.2026: "punkt" as a separate word — no letters before or after it — in any letter case; including "podpunkt" it would be 542) |
| Number of measurement strategies | THREE — the standard imposes none; the choice affects the number of measurements, the calculation and the uncertainty |
| Weighting curves | A-weighted levels (primary), also applicable to C-weighted levels |
| Uncertainty | Methods for estimating it are PART of the standard, not an appendix — a result without an uncertainty does not allow an exceedance to be judged |
| The most frequently overlooked exclusion | It does NOT apply to measuring ear exposure when hearing protectors are worn |
| Other exclusions | Masking of speech communication; infrasound, ultrasound and non-auditory effects of noise |
| Change of edition | PN-EN ISO 9612:2011 (Polish) WITHDRAWN 27-11-2025; the 2025-11 edition in force is available in English only |
| Change of title | Third element: "Engineering method" (2011) → "Methodology" (2025-11) |
| Strategy names and formulae | NOT GIVEN — we do not have the text of the standard (66 pages) |
| Status | In force — the PKN card of the 2025-11 edition carries neither the heading "Withdrawn" nor a "Date of withdrawal" row (checked 15 September 2026) |
Standard
- Standard number
- PN-EN ISO 9612:2025-11 (wersja angielska; wprowadza EN ISO 9612:2025 [IDT] oraz ISO 9612:2025 [IDT])
- Title (PL)
- Akustyka -- Wyznaczanie zawodowej ekspozycji na hałas -- Metodyka
- Title (EN)
- Acoustics — Determination of occupational noise exposure — Methodology (trzeci człon zmieniony wobec wydania z 2011, gdzie brzmiał „Engineering method”)
Step-by-step procedure
-
Establish the exposure conditions
Determine what the worker does, for how long and under what conditions. The scope of the standard names observation and analysis of the conditions as a prerequisite for controlling the quality of the measurements — it is not a preliminary activity but part of the method.
-
Choose the measurement strategy
From among the three described in the standard. THE NAMES ARE NOT GIVEN HERE — they are in its text. Record the choice: without it the result cannot be reconstructed.
-
Check the instrument
With an acoustic calibrator before and after the series. The meter must meet the requirements of PN-EN 61672-1 for the declared class.
-
Carry out the measurements
In accordance with the chosen strategy, under conditions of real work. Record the weighting curve (A or C).
-
Calculate the exposure level
The formulae are in the standard — we do not quote them, as we do not hold its text.
-
Estimate the uncertainty
By the methods given in the standard. Without an uncertainty it cannot be decided whether the result exceeds the limit value.
-
Record in the report
Give the full designation of the standard with its year, the strategy applied, the weighting curve and the uncertainty. A reference to "PN-EN ISO 9612" without a year does not distinguish the 2011 edition from that of 2025.
Required equipment and apparatus
| Equipment | Example | Indicative price |
|---|---|---|
| Class 1 sound level meter | Requirements for sound level meters are specified by PN-EN 61672-1 — a separate entry in this knowledge base; the exposure standard does not repeat them | — |
| Noise dosimeter (personal meter) | Worn by the worker through the shift; the choice between it and a stationary measurement follows from the strategy adopted | — |
| Acoustic calibrator | Check of the measurement chain before and after the measurement — a discrepancy invalidates the series | — |
Reagents, media and consumables
| Reagent | CAS | Details |
|---|---|---|
| No reagents | — | Measurement of a physical agent |
Health and safety (OHS)
- Measurements are carried out in noise — the person performing them is exposed as well and should wear hearing protection except at the moments when it would interfere with the measurement
- TECHNICAL NOTE: the result of this method does NOT describe the noise under a hearing protector — the standard expressly excludes such use
- TECHNICAL NOTE: ultrasonic noise is outside the scope of this standard and has its own limit values
Frequently asked questions
Which standard describes this test?
The test is performed according to PN-EN ISO 9612:2025-11 (wersja angielska; wprowadza EN ISO 9612:2025 [IDT] oraz ISO 9612:2025 [IDT]) — “Acoustics — Determination of occupational noise exposure — Methodology (trzeci człon zmieniony wobec wydania z 2011, gdzie brzmiał „Engineering method”)”.
How does this method work?
Noise exposure is a quantity referred to time: what is measured is not "the loudness in the hall" but the dose of sound a worker receives during a shift. The measurement consists in recording sound levels under conditions of real work and calculating the exposure level from them, the way of organising the measurement being chosen from among the three strategies described in the standard.
What is the measuring range and accuracy?
WHAT LABORATORIES DO WITH THESE THREE STRATEGIES (measurement on the scope database, reading of 23.09.2026): the standard is cited by 520 entries at 245 laboratories, and 491 entries at 237 laboratories cite it WITH A STRATEGY EXCLUSION — i.e. 94 % of the citations. Without any exclusion: 29 entries at 11 laboratories; WHICH STRATEGIES ARE EXCLUDED (measurement repeated on 23.09.2026 after the rule was corrected): strategies 2 and 3 together — 402 entries / 193 laboratories; strategy 2 alone — 24 / 13; strategy 3 alone — 65 / 31; records with an exclusion but without a strategy number — ZERO; citations without any exclusion — 29 / 11. THE ASSIGNMENT RULE, because the whole distribution depends on it: we take the fragment from the word "strategi" [the stem of the Polish word for strategy] up to forty characters further on and look in IT for the digits 2 and 3; an entry goes into the category "2 and 3" when both stand in this fragment. CORRECTION: the previous wording gave 187 / 218 / 50 / 36, and these were numbers from a rule requiring the digit DIRECTLY after the word. The most frequent record in the scopes reads "z wyłączeniem metody obejmującej strategię 2 i 3 – punkt 10 i 11" [excluding the method covering strategies 2 and 3 – clauses 10 and 11] (48 times with an en dash, 45 with a hyphen), and the second most frequent — "strategię 2 – punkt 10 i strategię 3 – punkt 11" [strategy 2 – clause 10 and strategy 3 – clause 11] (26 and 22 times): when searching for the digit three, the pattern hit the two and dropped out, so entries with BOTH strategies landed in the category "2 alone".; What this means for the client: a citation of "PN-EN ISO 9612" in an offer or in a test report does NOT say which strategy the measurement was performed with — and in the accreditation scopes nine out of ten entries are limited to some of the strategies of the standard. The strategy has to be checked in the scope of the laboratory, not in the number of the standard; Where this number comes from — a note on the notation: in the scopes, exclusions of strategies are written with the FULL WORD "punkt" [clause] ("z wyłączeniem metody obejmującej strategię 3 – punkt 11" [excluding the method covering strategy 3 – clause 11]), not with the abbreviation "pkt" or "p.". A pattern searching for the two abbreviations misses this class entirely — for this standard there are 317 such entries, and in the whole scope database 541 (measurement 23.09.2026: "punkt" as a separate word — no letters before or after it — in any letter case; including "podpunkt" it would be 542).
How long does the test take?
The procedure comprises 7 steps. The standard does not give a duration for every stage — the laboratory's own procedure decides.
What equipment is required?
Class 1 sound level meter, Noise dosimeter (personal meter), Acoustic calibrator.
Where is this test used?
Noise measurements at workplaces for the assessment of occupational exposure and the risk of hearing damage; Epidemiological studies of hearing damage and other adverse effects of noise; Setting priorities when planning noise control measures; Accreditation of occupational hygiene laboratories in the field of physical agents.
What safety precautions apply?
Measurements are carried out in noise — the person performing them is exposed as well and should wear hearing protection except at the moments when it would interfere with the measurement; TECHNICAL NOTE: the result of this method does NOT describe the noise under a hearing protector — the standard expressly excludes such use; TECHNICAL NOTE: ultrasonic noise is outside the scope of this standard and has its own limit values.
Which laboratory can perform this test?
The test is performed by laboratories accredited to ISO/IEC 17025. On LabCoda you can find them by the standard number PN-EN ISO 9612.