21 CFR § 874.3400 - Tinnitus masker.
(a) Identification. A tinnitus masker is an electronic device intended to generate noise of sufficient intensity and bandwidth to mask ringing in the ears or internal head noises. Because the device is able to mask internal noises, it is also used as an aid in hearing external noises and speech.
(b) Classification. Class II. The special control for this device is patient labeling regarding:
(1) Hearing health care professional diagnosis, fitting of the device, and followup care,
(4) Warnings for safe use, and