The use of different frequency response characteristics in everyday environments

Twenty-seven clients with mild to moderate, sensorineural hearing losses from two Australian Hearing Services (AHS) Centres trialed a programmable, two-memory hearing aid. The subjects were experienced hearing aid users but unfamiliar with the multiple memory concept. The aim of the test was to study the use of different frequency response characteristics in everyday environments. Each subject compared the NAL response with a linear Flatter response for three months, and compared the NAL response with a linear Steeper response for another three months. During the test periods the subjects completed prestructured diary forms that asked for a detailed description of the listening condition and a rating of the benefit obtained from each program on a scale from 0 to 10. Of 27 subjects, 5 preferred different frequency response characteristics in different listening conditions. Selected audiometric and hearing activity related parameters, or the fitting results failed to identify the five multiple memory users. The five subjects selected an alternative frequency response for listening in some noisy environments, but showed inconsistency in the reported listening conditions and responses they preferred. The results suggest that 1) a procedure for selecting candidates for multiple memory hearing aids is needed, and 2) a variation in the linear frequency response characteristic is a valid option as a second program.