Difficulty understanding speech in background noise is a common complaint of individuals with sensorineural hearing loss. Recent animal studies suggest this difficulty may be due, in part, to spiral ganglion cell degeneration related to aging or noise exposure. Although auditory brainstem response (ABR) thresholds and standard clinical audiometric tests are minimally affected by neuronal degeneration, the amplitude of wave I of the ABR is correlated to spiral ganglion cell density.