This work aims to develop wideband acoustic immittance (WAI) measures as a noninvasive auditory diagnostic tool, where WAI refers to the collection of both power-based and impedance-based measurements that include absorbance, power reflectance, impedance, and related quantities. Potential use of these measures includes (1) detection of fluid in newborn and young infant ears where tympanometry is less successful, (2) identification of the cause of a conductive hearing loss (e.g., fluid, disarticulated ossicle, fixed ossicle), and (3) monitoring changes in middle-ear stiffness that result from intracranial pressure changes. The work proposed here continues and formalizes the development of a normative database for WAI measures, which to date has been largely ad hoc. In particular, a database is proposed that will initially be populated with data collected from the proposed work and ultimately include procedures to allow for contributions of data from other researchers. The proposed work includes measurements on human subjects that are designed to determine how normative WAI measures depend on the parameters: instrumentation, age, gender, and race. The results will determine whether or not normative data would need to be parameterized for any of these quantities. A second emphasis of the proposed work is the research-based education of undergraduate students at Smith College, an all-women's liberal arts college. Undergraduate engineering students will be actively involved in all areas of the proposed work, with the goal of encouraging them to consider continuing their education toward a Ph.D.
Objective noninvasive medical tests do not exist for many problems that can occur within the auditory system. The development of a family of measurements known as wideband acoustic immittance has great potential for detecting a range of middle-ear problems with a simple sound measurement made in the ear canal. Ultimately this approach will lead to better methods for identification of the causes of hearing loss for all ages. The work proposed here will develop a normative data base for wideband acoustic immittance measures.