Auditory System Development and Dysfunction: What Do We Really Know about Childhood Hearing Loss?

Abstract

udiologists must have a thorough underA standing of normal auditory system function in order to diagnose hearing impairment and dysfunction. This is particularly true for the pediatric audiologist who works with a very young patient who may provide limited behavioral information. This background knowledge should include familiarity with auditory anatomy and physiology, psychoacoustics, and speech perception. The information comes to audiologists from a wide range of both human and animal studies, from studies of developing and mature auditory systems, and finally, from studies of both normally functioning systems and systems with auditory pathology. The academic background of audiologists provides this information from the first undergraduate class through the final graduate courses. However, in everyday practice, it is the working view of what constitutes an impaired auditory system that determines what audiologists actually do. The purpose of this article is to provide a framework for audiologists to guide their work with infants and children who may have hearing loss. An impaired auditory system may be characterized differently by the use of different criteria for dysfunction. Four different types of criteria will be discussed. These criteria include: a threshold criterion, a disease/dysfunction criterion, an audibility criterion, and an expanded audibility criterion. These criteria may be applied individually or together, depending upon the patient and his or her needs and presenting problems. In addition, the effects of auditory development on the use of these criteria in practice will be reviewed.