Preliminary studies on the use of an ABR amplitude projection procedure for hearing aid selection.

Hearing aid selection in young nonverbal children is difficult and objective selection procedures are needed. Kiessling (Scand Audiol 1982;11:269-275; Arch Otorhinolaryngol 1983;238:233-240) has proposed an objective hearing aid selection method based on an unaided ABR amplitude projection procedure. However, Kiessling's ABR projection method is based on the assumption that ABR amplitude is directly related to the loudness of a signal--an assumption which has not been tested. This assumption was investigated in a group of ten normally hearing and three hearing-impaired listeners. The results indicated that ABR amplitude measures obtained in a single trial do not always correlate well with perceived loudness, but ABR amplitudes averaged over several trials do correlate well with estimates of perceived loudness. The hearing-impaired listeners then participated in a second phase of the investigation in which hearing aids chosen by the ABR projection procedure were compared with hearing aids chosen by more conventional methods. The results indicated that the projection procedure prescribed appropriate gain and compression characteristics for two of the three hearing-impaired listeners.