Auditory neuropathy/auditory dys-synchrony is characterized by normal outer hair cell function and dys-synchronous neural responses. Otoacoustic emissions, auditory brainstem responses, and middle-ear muscle reflexes are valuable methods for clinical differentiation. Patients with auditory neuropathy/auditory dys-synchrony characteristically demonstrate difficulty understanding speech, particularly in situations with competing stimuli. Patients vary widely in auditory and other characteristics, and several possible underlying mechanisms are thought to be responsible for this hearing disorder.