Assessment of the middle-ear assumption of the auditory hazard assessment algorithm for humans

Abstract

The Auditory Hazard Assessment Algorithm for Humans (AHAAH) is an electrical equivalence model of the human ear designed to reproduce sound transmission from the outer into the inner ear in order to predict potential injury from a given sound exposure. This model was generated and validated using a (mostly) feline model, thus several key assumptions may not hold when adapted to the human. The current project aims to test some of these assumptions, such as the effects of middle-ear muscle contraction (MEMC) on sound transmission and whether the MEMC can be elicited by a conditioning stimulus prior to sound exposure (i.e., a “warned” response). In order to quantify the MEMC, we use laser-Doppler vibrometry to measure tympanic membrane motion in response to a reflex-eliciting acoustic impulse. After verifying the MEMC, we will attempt to classically condition the response by pairing the reflex-eliciting acoustic impulse (unconditioned stimulus, UCS) with a light from a LED display (conditioned stimulus, CS)....