Waveguide modeling as a tool for fitting a hearing aid

Abstract

A physical modeling method is used to develop a model of the acoustical elements of a hearing aid and to examine its properties. This model enables one to design an acoustical element having desired frequency characteristics, thus providing the acoustical system well fitted to the individual patient’s needs. The acoustical system of the hearing aid is treated as a waveguide—a long and narrow tube. Modeling methods similar to the ones applied to human vocal tract synthesis are used. The system is divided into several cylindrical sections. Physical phenomena present in the acoustical system (wave reflections, frequency-dependent damping, etc.) can be implemented directly in the model. By adjusting the parameters of the model, one is able to examine acoustical properties of various systems, having different shapes and dimensions. This method may be helpful for the audiologists during the process of hearing aid fitting.