Figure 7.

Physiological and anatomical changes in a cochlea with permanent threshold shift resulting from noise exposure. The graphs on the right map the damage to the cochlear hair cells in terms of presence or absence of cells (top panel) and proportion of hair cells with stereociliar abnormality (lower panel). On the top right is a sample of frequency tuning curves of neurons originating in cochlear frequency regions (A–F) near to the damaged cochlear area. The dashed curves represent normal tuning from control animals. The data points in the lower left-hand diagram are the minimum thresholds of cochlear neurons compared with normal values (continuous curve). Adapted from Liberman and Mulroy [21].