Hearing loss and the limits of amplification.

This review article summarizes the effects of sensorineural hearing loss on the recognition of amplified speech, both for speech presented in quiet and in a noise background. Some hypotheses are presented regarding the underlying damage in the cochlea that leads to the deficits in speech recognition for hearing losses of various configurations. For severe hearing losses in the high frequencies, amplification is often ineffective. While the existing data also suggest that sensorineural hearing loss can lead to poor frequency resolution, which leads to problems understanding speech in noise, the frequency resolution of the cochlear implant is usually even poorer. Therefore a strategy of preserving low-frequency residual hearing combined with electrical stimulation for the higher frequencies is an attractive solution for patients with severe high-frequency hearing loss.