Julius Golstein

10:30 am on Friday, November 22, 2019
12:00 pm on Friday, November 22, 2019
ERB 401, 44 Cummington Mall, Boston, MA 02215
Title: Application of the Classical Phon-Loudness Model to Reveal Middle-Ear and Acoustic-Reflex Functions Equal Loudness-level Contours (Fletcher and Munson, 1933) measured by Lydolf and H. Moller (1997) show increases in ELC growth rates at each frequency with loudness above 60 phons and below 1 kHz, suggesting the influence of acoustic reflex attenuation. Classical psychophysical power-law models (Stevens, 1966) were fit to ELC data (20 - 80 phons) judged to be free of reflex attenuation. The higher level ELC data exceed extrapolated predictions from the low-level models. These ELC differences are modeled as reductions in middle ear input. The majority of these differences represent acoustic-reflex attenuation of middle-ear input, with log-linear growth rates <1>1 dB/dB are interpreted as middle-ear attenuation from unmonitored static eardrum pressure assumed to accompany low-frequency pressure-field stimuli. Both mechanisms add middle ear attenuation by increasing the stiffness of stapes motion, and can be modeled as mass-spring-dashpot systems (Kringlebotn and Gundersen, 1985; Kringlebotn, 2000). A model of reflex attenuation dynamics (Goldstein, 2014) based on the acoustic-reflex power-law behavior, represents the salient features of ipsilateral eardrum impedance modulation (A. Moller, 1962). Acoustic reflex properties from this study and Rabinowitz (1977) are compatible.