Sound Source Localization in 3D using Asymmetrical Positioned and Skew Aligned Two-Array Microphone - Experimentation

A human is capable detecting sounds coming from all directions around him. The quest to develop cognition in a robot has opened many opportunities for researchers. In robots, sound source detection has been researched for decades and is successful in detecting in 2D as well as 3D. This paper focuses on an experimental setup that is developed to imbibe hearing cognitive in a robot. 3D sound source localization is achieved using only 2 microphones. Our experiment goes beyond the human cognition by utilizing animal cognition for sound localization that considers perceptual capabilities of humans. Barn owl ear alignment is being used as reference for robot ear alignment. The ear alignment in Barn owl is not symmetrical but one ear is at higher location than the other. To be more specific, the paper is related to directional (but not distance of sound source) sound source localization in a robot in three-dimensional space, using only two microphones; wherein the microphones are positioned asymmetrical in the robot head to form skewed alignment and one microphone is rotated to create the skew alignment at different angles between the microphones. The location of a sound source is determined by studying the TDOA computed from sound signal recorded at the different angles between the microphones.