Biomimicry Sound Source Localization with "Fishbone"

Abstract

Human can localize a sound source even when it is on the median plane. The sense of elevation like this is called as monaural sound source localization. The cues are said to be generated by the reflection on the pinna as the elevation-dependent dips (zeros) of the spectral distribution. In human auditory system, they are detected by cochlea. In this paper, by using Fishbone sensor for direct frequency decomposition of the incident sound, we realize this principle as a novel sensor system which consists of 1) a logarithmic spiral reflector mimicking the human pinna, and 2) a Fishbone sensor mimicking human cochlea. We describe a theory for an optimal shape of a reflector (pinna). We show a design and fabrication of the overall system and experimental results using it.