Otoacoustic emissions (OAEs) are sounds produced by the inner ear that can be measured in the ear canal. There are different types of OAEs including spontaneous, stimulus frequency, transient evoked, and distortion product OAEs. OAEs are believed to be generated by outer hair cells in the cochlea and are reduced or absent when outer hair cell function is impaired. Brainstem auditory evoked response (BERA) testing objectively measures electrical activity in the auditory pathway generated in response to auditory stimuli. BERA waveforms provide information about auditory nerve and brainstem function. Abnormalities in BERA wave latencies, amplitudes, and morphology can indicate lesions