The goal of this research is to evaluate a comprehensive test battery of new wide-bandwidth, i.e., wideband (WB), acoustical tests of auditory function in the differential diagnosis of middle ear, cochlear and neural pathologies in a population of Veterans. WB tests refer to ear canal tests using sound responses measured from 0.2 kilohertz (kHz) to frequencies as high as 8 kHz, a bandwidth that is critical for speech perception. There will be tests in the battery for middle-ear assessment using power absorption, cochlear assessment using otoacoustic emissions (OAEs) and the acoustic stapedius reflex (ASR) using middle ear power absorption. Results will be compared with a standard single-frequency clinical immittance test battery routinely used in the assessment of auditory function in Veterans. Aim 1 seeks to evaluate the accuracy of the WB test battery in the differential diagnosis of middle-ear pathology and related conductive hearing loss by comparing the sensitivity and specificity of the WB battery to the traditional immittance battery for the following disorders common in Veterans: tympanic membrane perforation, serous otitis media, cholesteatoma, and otosclerosis. Aim 2 seeks to modify a WB ASR test to provide automatic detection of the ASR threshold for comparison with the traditional single-frequency ASR threshold. Aim 3 seeks to validate the use of Transient-evoked otoacoustic emission (TEOAE) and spontaneous otoacoustic emissions (SOAEs)tests in Veterans to assess cochlear status, and evaluate their test performance in classifying ears with normal hearing and sensorineural hearing loss. Finally, Aim 4 seeks to compare the diagnostic accuracy of the full WB test battery with the full single-frequency admittance test battery to detect any type of hearing loss including sensorineural, conductive and mixed. The hypothesis is that the WB test battery is more accurate than the traditional immittance test battery in identifying ears with normal auditory status and ears with a range of risks for auditory pathology.