A COMPUTATIONAL MODEL FOR TYMPANOMETRY

A computational model for tympanometry was developed by describing the ear canal with the impedance theory of a tube and by representing the middle ear with the Zwislocki electroacoustic analog. Changes in ear- canal length and acoustic properties of the middle ear with ear-canal pressures during a tympanometric procedure were mimicked by manipulati ng relevant model parameters. Tympanograms of different patterns of th e normal ear and the ear with a disarticulation of the ossicular chain were reproduced with the model and were in agreement with experimenta l observations reported by other investigators. The model demonstrated the relationship between various patterns of admittance tympanograms and middle ear impedance predicted by the Vanhuyse theory. The effects of the ear canal on the estimates of middle ear admittance using comp ensation procedures for ear-canal volume were also predicted with the model. The model can provide a better understanding of the mechanism o f tympanometry and a framework for further modeling study. (C) 1996 Ac oustical Society of America.