| ANSI S3.1 (Reaffirmed 2013) American National Standard Maximum Permissible Ambient Noise Levels for Audiometric Test Rooms |
| Recognition Date | 2014-07-09 |
| Recognition List | 036 |
| Recognition Number | 4-160 |
| Extent | Complete standard |
| Standards Orgs | ANSI American National Standards Institute https://www.ansi.org/ |
| STG | Dental/ENT |
| FDA Tech | Shu-Chen Peng FDA/OMPT/CDRH/ODE/DOED/ENTB/ 301-796-6481 shu-chen.peng@fda.hhs.gov |
This standard is relevant to medical devices and is recognized on its scientific and technical merit and/or because it supports existing regulatory policies.
Hearing measurements in an audiometric test room may be conducted for different audiometric purposes over different test frequency ranges. However, if the ambient noise level is excessively high, some hearing threshold levels measured in that environment will be inaccurate. This occurs because excessively high ambient noise will create an elevation of hearing threshold levels. This is a psychoacoustic phenomenon called masking.
Exclusion of all ambient noise from an audiometric test room is not feasible nor practical from structural and cost considerations. However, to ensure that hearing tests are not influenced by excessive ambient noise masking, there is a need to specify maximum permissible ambient noise levels (MPANLs) that can be allowed in an audiometric test room. This is true particularly when testing is done at sound pressure levels for pure tones corresponding to 0 dB hearing level. Further, there is a need to specify MPANLs for different audiometric conditions, test frequency ranges, and earphone types that will permit testing at reference equivalent threshold levels specified in ANSI S3.6- 1996 American National Standard Specification for Audiometers.
This Standard includes the specification and measurement of MPANLs in an audiometric test room. Within this Standard, MPANLs are specified for octave and one-third octave band intervals from 125 to 8000 Hz for the audiometric conditions of testing with ears covered using a supra-aural and insert earphone and ears not covered for the test frequency ranges 125 to 8000 Hz, 250 to 8000 Hz, and 500 to 8000 Hz.
| Regulation Number | Device Name | Device Class | Product Code |
| §874.3950 | Hearing Aid, Air Conduction, Transcutaneous System | Class 2 | NIX |
| §874.3400 | Masker, Tinnitus | Class 2 | KLW |
| §874.3300 | Hearing Aid, Bone Conduction | Class 2 | LXB |
| §874.3300 | Hearing Aid, Bone Conduction, Implanted | Class 2 | MAH |
| §874.3300 | Hearing Aid, Air Conduction | Class 1 | ESD |
| §874.1090 | Tester, Auditory Impedance | Class 2 | ETY |
| §874.1090 | Tympanometer | Class 2 | NAS |
| §874.1080 | Set, Audiometer Calibration | Class 1 | EWA |
| §874.1060 | Chamber, Acoustic (For Audiometric Testing) | Class 1 | EWC |
| §874.1050 | Audiometer | Class 2 | EWO |
| Unclassified | Implant, Auditory Brainstem | Class 3 | MHE |
| Unclassified | Implant, Cochlear | Class 3 | MCM |
| Unclassified | Implant, Hearing, Active, Middle Ear, Partially Implanted | Class 3 | MPV |
| §874.3950 | Hearing Aid, Air Conduction, Transcutaneous System | Class 2 | NIX |
| Class II Special Controls Guidance Document: Transcutaneous Air Circulation Hearing Aid System (TACHAS); Guidance for Industry and FDA. Document issued on November 7, 2002 Guidance for Industry and FDA Staff Implantable Middle Ear Hearing Device Document issued on: August 1, 2003 Draft Guidance for Industry and FDA Staff Class II Special Controls Guidance Document: Tinnitus Masker Devices. Document issued on November 8, 2005 Guidance for Industry - Noise Claims in Hearing Aid Labeling Document issued on: October 21, 1998 |