FUZZY NEURAL SYSTEMS FOR CONTROLLING SOUND LOCALIZATION IN STEREOPHONIC REPRODUCTION

The paper presents a new fuzzy logic control (FLC) approach which lead s to a stereophonic reproduction controller for localising an auditory image in the desired direction and at the expected distance. Since an auditory event is usually less precisely resolved than the physical s ound space, the auditory event need not coincide with a physical sound source, and can occur at a position where nothing is visible to a lis tener. It turns out that controlling the auditory image is more diffic ult than the localisation of a sound image. Unlike the conventional so und image localisation approach, our fuzzy logic controller can take a ccount of knowledge in human auditory perception. The ambiguous human auditory perception in conjunction with the spatial reverberation from the surrounding environment can be represented by a number of fuzzy-s et values. From these fuzzy representations, the auditory image locali sation controller characterises the function of how control outputs de pend on control inputs as fuzzy implications or associations. Furtherm ore, the overall stereophonic reproduction controller can be realised by a 45-rule fuzzy associative memory (FAM) system. The performance of FLC-based auditory image localisation is verified in a number of expe riments.