A large number of different components of the auditory evoked potential can be recorded from the human scalp using averaging techniques. It is now possible to evaluate with such evoked potential measurements the functioning of the entire human auditory system from the hair cell receptors to the association areas of cortex. This multiplicity of evoked potential components is important clinically since any one component measurement may be the most appropriate for a certain subject at a certain time, and also because the replication of objective audiological findings using more than one testing method allows greater confidence in the results. As well as providing an accurate means of determining the extent of a hearing loss, evoked potential studies can also provide information concerning the type and location of such a defect.