Electroacoustic characterization of hearing aids: a system identification approach

The accurate electroacoustic characterization of hearing aids is important for the design, assessment and fitting of these devices. With the prevalence of modern adaptive processing strategies (e.g., level-dependent frequency response, multi-band compression etc.) it has become increasingly important to evaluate hearing aids using test stimuli that are representative of the signals a hearing aid will be expected to process (e.g., speech). Nearly all current hearing aid tests use stationary test signals that can characterize only the steady-state performance of a hearing aid. The present research examines the characteristics of automatic signal processing hearing aids with natural-speech input signals that may cause the hearing aid response to time-vary. They have investigated a number of linear system identification techniques that can be used to develop time-varying models of hearing aids. Using these models, one can begin to characterize performance of hearing aids with real-world signals and explore speech-based transient distortion measures.