Every year millions of hearing tests are conducted in the U.S. for a variety of reasons, including diagnosis of ear disease, evaluation of communicative function, monitoring effects of noise and ototoxic medications. prospective research studies, and fitting of hearing aids. Although there is a "standard" hearing test method, the rules are vaguely defined and loosely followed. This project is designed to develop an automated method for testing hearing sensitivity. It is designed to achieve similar test results to those obtained by expert audiologists while standardizing the method, eliminating errors, increasing efficiency, and decreasing cost. The method preserves the salient features of routine audiometry while applying well-accepted principles of auditory psychophysics. Contralateral masking is presented to the non-test ear whenever the test signal may be audible in that ear. In addition to automating the sequence and timing of stimuli, the method provides quality indicators that alert the audiologist to potential errors due to patient factors or inappropriate masker levels. In this Phase I project, a testable prototype will be developed, preliminary testing will be conducted on normal-hearing and hearing-impaired adult subjects, and modifications to the prototype will be made based on the preliminary evaluation. PROPOSED COMMERCIAL APPLICATION: Hearing tests conducted by audiologists in the U.S. number in the millions per year. The automated method that will be developed in this project has advantages of standardization, increased efficiency, greater accuracy, and reduced cost. The method is expected to be a software add-on to new audiometers and a retrofit to existing audiometers. There are about 1200 audiometers sold annually in the U.S. an additional 800 outside the U.S. Because the method will add a small increment (about 10%) to the cost of audiometers, the takeup rate is expected to be high.