(a) Identification.
         A hearing aid is wearable sound-amplifying device that is intended to compensate for impaired hearing. This generic type of device includes the air-conduction hearing aid and the bone-conduction hearing aid, but excludes the group hearing aid or group auditory trainer ( § 874.3320 ), master hearing aid ( § 874.3330 ), and tinnitus masker ( § 874.3400 ).
     
    
        
        (b) Classification.
        
        (1) 
         Class I (general controls) for the air-conduction hearing aid. The air-conduction hearing aid is exempt from the premarket notification procedures in subpart E of  part 807 of this chapter subject to  § 874.9.
     
    
        
        (2) 
         Class II for the bone-conduction hearing aid.
     
    
        
            Code of Federal Regulations
        
        [51 FR 40389, Nov. 6, 1986, as amended at 65 FR 2316, Jan. 14, 2000]
    
    
        
        (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.
     
    
        
        (b) Classification.
         Class II.