Neurochemical basis of auditory fatigue: a new hypothesis

Neuroactive polypeptides such as substance P and enkephalin have recently been demonstrated in the neuronal elements of the inner ear. It has been suggested that the same neuropeptides have a transmitter role in various sensory systems. Transmitter roles for the neuropeptides in the cochlear processes could provide new explanations for many physiological phenomena of hearing. The neuropeptides are particularly well suited to explain such a noise-induced auditory overloading condition as temporary threshold shift.