Section 874.1120 - Electronic noise generator for audiometric testing(a)Identification. An electronic noise generator for audiometric testing is a device that consists of a swept frequency generator, an amplifier, and an earphone. It is intended to introduce a masking noise into the non-test ear during an audiometric evaluation. The device minimizes the non-test ear's sensing of test tones and signals being generated for the ear being tested.(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 .51 FR 40389, Nov. 6, 1986, as amended at 84 FR 71813 , Dec. 30, 2019