The clinical utility of expressing hearing thresholds in terms of the forward-going sound pressure wave.

Objective: To assess the clinical utility of quantifying pure-tone hearing thresholds in terms of the forward-going sound pressure wave.

Design: Sound pressure measurements in the ear canal were used to derive, with hearing threshold measurements, hearing thresholds expressed in terms of the forward-going sound pressure wave, hearing thresholds based on coupler-based calibration, and hearing thresholds expressed in terms of the sound pressure measured at the microphone.

Study Sample: Fifty-two adults, 18 to 34 years of age, served as the study group.

Time-domain "wave" model of the human tympanic membrane.

Middle ear models have been successfully developed for many years. Most of those are implemented in the frequency domain, where physical equations are more easily derived. This is problematic, however, when it comes to model non-linear phenomena, especially in the cochlea, and because a frequency-domain implementation may be less intuitive.

Wave model of the cat tympanic membrane.

In order to better understand signal propagation in the ear, a time-domain model of the tympanic membrane (TM) and of the ossicular chain (OC) is derived for the cat. Ossicles are represented by a two-port network and the TM is discretized into a series of transmission lines, each one characterized by its own delay and reflection coefficient. Volume velocity samples are distributed along the ear canal, the eardrum, and the middle ear, and are updated periodically to simulate wave propagation.