New techniques of hearing assessment

This article reviews current literature in the areas of otoacoustic emissions and auditory brain stem responses (ABRs) and their application to the evaluation of peripheral auditory function in infants and children. The different types of otoacoustic emissions are described along with their incidence, development, clinical applications, and interpretation in the pediatric group. The development of the auditory system, reflected by ABRs, is presented in detail with previously unpublished results from three- channel Lissajous' trajectory studies performed in infants. Clinical application of frequency-specific ABRs, both air and bone conducted, are presented. Finally, a discussion of the need to develop objective estimators of signal quality and threshold detection for otoacoustic emissions and ABRs in infants and children is presented, which includes previously unpublished results evaluating a new technique.