Written and maintained by CASRAI Editorial Board
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General product and regulatory information, not medical advice and not a substitute for guidance from an audiologist or occupational health professional.
Short answer
An audiometric booth is an enclosure used to keep background noise low during hearing tests. The U.S. rule that sets the noise limit does not mention booths: OSHA 29 CFR 1910.95 Appendix D limits background sound pressure levels in the rooms used for audiometric testing, with a maximum of 40 dB at 500 and 1000 Hz, 47 dB at 2000 Hz, 57 dB at 4000 Hz and 62 dB at 8000 Hz. A booth is one way a site can meet a room limit; it is not itself the requirement.
What an audiometric booth is
An audiometric booth (also searched as a ‘sound booth for hearing test’) is a purpose-built enclosure in which a person sits while an audiometer presents tones through earphones. Its job is to lower the noise reaching the test ear so that quiet tones can be heard and recorded. The word is used loosely: product pages, building specifications and clinic checklists use ‘booth’, ‘room’ and ‘suite’ for related setups. The regulation text uses ‘rooms’.
A booth lowers background noise; it does not remove it. The Appendix D limits below are not zero, which is why the limit is stated as a ceiling per frequency band.
How background noise is limited: OSHA Table D-1
Appendix D of 29 CFR 1910.95 states that rooms used for audiometric testing shall not have background sound pressure levels exceeding those in Table D-1. The levels are maximum octave-band sound pressure levels (OSHA, checked 2026-10-31).
| Octave-band center frequency | Maximum background level |
|---|---|
| 500 Hz | 40 dB |
| 1000 Hz | 40 dB |
| 2000 Hz | 47 dB |
| 4000 Hz | 57 dB |
| 8000 Hz | 62 dB |
The same appendix says the measurement must be made with equipment conforming at least to the Type 2 requirements of American National Standard S1.4-1971 (R1976) for sound level meters and the Class II requirements of S1.11-1971 (R1976) for octave-band filter sets. Source: OSHA 29 CFR 1910.95 Appendix D, checked 2026-10-31.
What the appendix does not do: it sets no construction rule for a booth and does not say a booth is required. Whether a given room or booth meets Table D-1 is a measurement result for that location, not a property of a product category.
Booth, quiet room or portable setup
Because the limit attaches to the room where testing happens, the same Table D-1 applies to whichever setting a program uses. Related CASRAI supply checklists cover the clinics where hearing tests are done:
- Audiology clinics: see the audiology clinic supply checklist.
- Occupational medicine clinics: see the occupational medicine clinic supply checklist.
- Hiring and pre-placement testing: see the pre-employment physical exam supply checklist.
OSHA 29 CFR 1910.95 paragraph (h)(4) says audiometric examinations shall be administered in a room meeting the requirements listed in Appendix D, and paragraph (g)(5)(ii) refers to mobile test vans used for audiometric testing (OSHA, checked 2026-10-31). The rule is written around the measured noise level of the room, not around a particular piece of furniture.
Booth noise versus audiometer calibration
Two checks are often mixed up because both concern ‘the hearing test setup’, but they measure different things:
| Check | What it covers | What OSHA states |
|---|---|---|
| Background noise in the test room | Ambient sound pressure level in the space | Appendix D: not above Table D-1, measured with Type 2 meter and Class II filters |
| Audiometer calibration | The levels the audiometer actually delivers | Appendix E: calibration shall be checked acoustically at least annually; an exhaustive calibration is required if deviations are greater than 15 dB at any test frequency |
Source for the second row: OSHA 29 CFR 1910.95 Appendix E, checked 2026-10-31. A quiet booth does not make an out-of-calibration audiometer accurate, and a calibrated audiometer does not make a noisy room acceptable. The device side is covered in audiometer types as FDA and OSHA describe them.
Common misunderstandings
‘OSHA requires a booth.’
No. Appendix D limits background levels in rooms used for audiometric testing and does not use the word booth. Paragraph (h)(4) of the rule likewise refers to a room meeting Appendix D.
‘A booth is soundproof.’
The regulatory limits are finite decibel values per band, so the working goal is a measured level below a ceiling, not silence.
‘Booth certification replaces calibration.’
They answer different questions. Appendix E concerns the audiometer’s acoustic output; Appendix D concerns the room’s background noise.
FAQ
What is an audiometric booth?
An enclosure used to keep background noise low during hearing tests, so that the quietest tones presented by the audiometer can be heard.
Is a sound booth for a hearing test required by law?
The OSHA hearing conservation rule does not require a booth. It limits background noise in the rooms used for audiometric testing to the Table D-1 levels.
What background noise level is allowed in an audiometric test room under OSHA?
No more than 40 dB at 500 and 1000 Hz, 47 dB at 2000 Hz, 57 dB at 4000 Hz and 62 dB at 8000 Hz, measured in octave bands with Type 2 and Class II equipment.
How often must the audiometer be calibrated?
OSHA Appendix E says audiometer calibration shall be checked acoustically at least annually.
Sources
All sources checked 2026-10-31.
