Signal-processing techniques in a computerized hearing aid test system.

General background is given to describe the factors leading up to the implementation of a computerized hearing aid test system in a production environment. The digital measurement methods for determination of the required acoustal components such as fundamental, rms, distortion, etc., in the presence of noise are discussed. The use of the concept of the average cycle for repetitive signals is described with its advantages in a Fourier type system. An algorithm for measuring rms for nonrepetitive signals that trades off resolution for memory size is described. Features and advantages of computerized testing of hearing aids are listed.