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Hearing warning signals and speech with hearing protection

People wearing hearing protection hear the noise less, but also warning signals and conversation. The risk assessment must take this into account. This guide summarises what DGUV Rule 112-194 says about listening tests, markings and directional hearing.

As of 17 October 2026, DS SafetyWear Arbeitsschutzprodukte GmbH

The problem

With hearing protection people speak more quietly, and signals can be missed. The risk assessment must also consider indirect hazards, for example when noise interferes with the perception of warning signals (section 3(3) of the German Noise and Vibration Ordinance; the UK regulations list warning signals among the factors in regulation 5(3)). Under DGUV Rule 112-194 (section 6.2.7), too much attenuation is not permitted if warning signals, warning calls, information-bearing sounds or communication matter (overprotection).

Markings for signal audibility

Markings according to DGUV Rule 112-194, section 6.5
MarkingMeaningNote
Wsuitable for warning signals, information-bearing sounds and speechmean slope of the octave-band attenuation from 125 to 4000 Hz of at most 3.6 dB per octave; an individual listening test is still needed
Xextremely flat frequency responseat most 2 dB per octave; the difference between the H and L values is usually at most 7 dB; recommended for musicians or people with impaired hearing, for example
Strack construction (railways)special requirement set by the authorities, plus an individual listening test
Vroad trafficspecial requirement set by the authorities, plus an individual listening test
E1 to E3railway operationspecial requirement set by the authorities, plus an individual listening test

Where there are no special requirements, hearing protection with a flat frequency response is recommended. The smaller the difference between the H and L values, the more evenly a hearing protector attenuates; the values of all EarProtect models are under attenuation values, the explanation under SNR and H/M/L.

Listening tests

  • Speech: communication is to be checked by listening tests under operating conditions, also for hearing protectors with the marking W (section 7.7.1).
  • Information-bearing work sounds: a listening test is needed in every case; getting used to the changed hearing impression may be necessary (7.7.2).
  • Warning signals: they must be clearly perceptible with the hearing protection, otherwise the noise must be reduced or the signal changed. Before first use, listening tests under DIN EN ISO 7731 annex C are needed (7.7.3).
  • Track construction (S): daily listening tests. Road traffic (V): at least every three years. Railway (E1 to E3): every three years plus a daily check of radio intelligibility.

Directional hearing

Earmuffs make it harder to locate sound sources and are often rejected for work on vehicles. Earplugs usually help there (sections 6.4.2 and 7.7.4). Further criteria are in Earplugs or earmuffs?.

With existing hearing loss

People with impaired hearing understand less even without hearing protection, and even less with it. Communication may become impossible already below 85 dB(A). The risk assessment must then be adapted, for example with visual signals, radio or hand signals (section 7.7.5).

What companies can do

  1. Record all warning signals and important sounds at the workplace (risk assessment).
  2. Reduce noise or change signals if they are not clearly perceptible with hearing protection.
  3. Choose hearing protection with a flat frequency response and run listening tests under operating conditions.
  4. With respiratory protection, make sure that the acoustic warning signals of the respirator stay audible (section 7.9.3).
  5. Practise hearing speech and warning signals in training.

Frequently asked questions

Can you still hear warning signals with hearing protection?

That has to be checked. Warning signals must be clearly perceptible with the hearing protection; otherwise the noise must be reduced or the signal changed. Listening tests under DIN EN ISO 7731 annex C are needed before first use.

What does the marking W on hearing protection mean?

The hearing protector is suitable for warning signals, information-bearing sounds and speech: the mean slope of the octave-band attenuation from 125 to 4000 Hz is at most 3.6 dB per octave. An individual listening test is still needed.

How often are listening tests needed?

It depends on the use: before first use, daily in track construction, at least every three years in road traffic, every three years plus a daily radio-intelligibility check for train drivers.

Which hearing protection suits people who must hear the direction of sounds?

Usually earplugs. Earmuffs make it harder to locate sound sources (sections 6.4.2 and 7.7.4).

Sources

Further reading