| ANSI S3.4-2007 (Reaffirmed 2017) American National Standard Procedure for the Computation of Loudness of Steady Sounds |
| Recognition Number | Dental/ENT |
| Recognition Date | 2019-01-14 |
| Recognition List | 051 |
| Recognition Number | 4-162 |
| 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.
This standard specifies a procedure for calculating the monaural and binaural loudness of steady sounds as perceived by listeners with normal hearing. The procedure is based on the spectra of the sounds. The possible sounds include simple and complex tones (both harmonic and inharmonic), bands of noise and mixtures of tones and noise. The spectra can be specified exactly, in terms of the frequencies and levels of individual spectral components, or approximately, in terms of the levels in 1/3 octave bands covering center frequencies from 50 to 16,000 Hz. The standard is applicable to sounds presented in free field with a frontal incidence, in a diffuse field, or listening via headphones.
| 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, Air Conduction | Class 1 | ESD |
| §874.3300 | Hearing Aid, Bone Conduction | Class 2 | LXB |
| §874.3300 | Hearing Aid, Bone Conduction, Implanted | Class 2 | MAH |
| 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 |
| There is no relevant guidance developed at this time. |