Modelling of the peripheral auditory system demonstrated at the human perception of loudness

Dissertation (26.843 KB)

This thesis deals with methods and implementations of functional models of the peripheral auditory system. Connections to applications like loudness or noise measurement systems are discussed. In contradiction to the dB(A), the proposed dB(ELC) takes into account the entire hearing area by using a level-dependent magnitude response adaption.

Furthermore a nonlinear model of the peripheral auditory system is proposed. This model is based on the power-spectrum model of masking. It consists of two main stages: outer-middle ear filtering and a nonlinear bank of bandpass filters which simulate the inner ear. The magnitude response of the outer-middle ear filter is estimated from the equal loudness contours. The nonlinear bandpass filters are derived from linear gammatone filters consisting of 4 biquad sections. Therefore the model can be used with different methods of control level calculations. Another advantage are the control level independent center frequencies and orders of the bandpass filters. This model offers a basic concept for a level-dependent calculation of the time-frequency analysis performed in the inner ear. It can be used as a pre-processor for applications like noise measurement and speech recognition systems, the developement of hearing aids or the qualitiy assessment of audio devices.