BINAURAL HEARING PLATFORM FOR FUTURE HEARING AID RESEARCH : Implementation in Matlab Audio Processing framework

Abstract: Binaural technology is used to recreate realistic sound to the listener. How- ever, many signal processing and noise cancellation techniques do not pre- serve the binaural characteristics of the binaural sound and thus destroying the realism. Binaural technologies are used in various applications like hear- ing aids, auditory displays, echo location for the blind, etc. The heart of binaural technology is the Head Related Transfer Functions which provide the transfer functions of the human pinnae, the shoulders etc. These Head Related Transfer Functions provide the Inter aural Level Di erences that contributes to the binaural sound. Apart from the Head Related Transfer Functions there are many other cues like the Inter Aural Time di erences in binaural hearing that provides information about the nature and location of the source. The Inter Aural Time di erences are known to contribute to the localization at low frequencies and the Inter aural Level Di erences contribute to localization at high frequencies. This thesis provides a design solution for reproducing the sound eld (preserving the binaural cues) with the help of microphone arrays placed on either side of the listener's ears. The primary work in this thesis is to build a model of a binaural hearing system and implement it in real time using the Matlab Audio Processing framework. This provides a binaural platform for further enhancements like noise reduction and speech enhancement, etc. The system is evaluated mathematically and perceptually. The results show that the platform tracks a single user very accurately and perceptual tests show that the system can be used to localize sounds in the azimuthal plane.