{"data":{"id":"us/21-cfr-874.3330","jurisdiction":"us","citation":"21 CFR 874.3330","heading":"Master hearing aid.","body":"(a) Identification. A master hearing aid is an electronic device intended to simulate a hearing aid during audiometric testing. It has adjustable acoustic output levels, such as those for gain, output, and frequency response. The device is used to select and adjust a person's wearable hearing aid.\n(b) Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 874.9.","path":["Title 21—Food and Drugs","CHAPTER I—FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES","SUBCHAPTER H—MEDICAL DEVICES","PART 874—EAR, NOSE, AND THROAT DEVICES","Subpart D—Prosthetic Devices"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-21.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:47Z","sha256":"b64c413c55b4e516177f8af4d8f07fab05cf9060c84c88cd00a0312bc691fdce","source_id":"us-cfr","stale":true,"prev":"us/21-cfr-874.3325","next":"us/21-cfr-874.3340"},"notice":"GroundRules: Original legal text. Not legal advice."}