ABSTRACT
This chapter covers the topic of hearing loss, its measurement and diagnosis. Hearing disabilities often occur in the later years. For the young, hearing loss is even more tragic because of the far-reaching consequences of this disability. A child with profound hearing loss may never develop the use of normal language. A typical audiogram obtained for two different hypothetical patients. Patient A shows a relatively flat loss of about 30 dB at each frequency. To understand exactly what this loss means people have plotted next to the audiogram the actual threshold obtained by Patient A on a graph of log frequency versus sound pressure level. Differences in hearing level for airborne and bone-conducted tests are diagnostic of the type of hearing impairment. Although the pure tone audiogram is the principal measure of hearing level, the most important social and practical implication of hearing impairment is the inability to hear speech. Such impairment causes the individual great hardship.
