Thus, every adjustment of the hearing aid appears instantly on the display, making fine tuning a hearing aid easy work. The speech-shaped composite signal can be used to test gain and output. A flat composite test signal is also available when needed. Many professionals find that IM distortion has more effect on sound quality and speech intelligibility than harmonic distortion. The composite signal also conforms to the ANSI S3.41-1992 standard.
Bias tones are available to test the action of the filters on the hearing aids.
ANSI '96 and Other Standards Frye Electronics remains strongly committed to testing by industry standards. ANSI '96 is a revision of the ANSI '87 standard. It more accurately and thoroughly tests AGC aids, and the telecoil test has been changed to provide results that are more practical, more meaningful. A special telewand, with the proper field strength, is included when you order the ANSI '96 sequence. A menu choice allows proper testing of adaptive-AGC hearing aids.