Ormia ochracea Inspired Single-Microphone Approach for 3-D Sound Localization

The world has increasingly recognized the significance of sound source localization (SSL) for enhancing robot–environment interactions, and with time, its demand is only increasing. The role of SSL extends beyond mere auditory detection, facilitating tasks such as navigation and human–robot communication. Traditional SSL approaches, however, grapple with limitations, such as high computational demands and the necessity for multiple sensors, which compromise system simplicity and accuracy. Addressing these challenges, this study presents an innovative approach to 3-D SSL using a single fly-inspired MEMS directional microphone (DM). Our design capitalizes on the polar pattern response of the DM, which was calculated at different distances, frequencies, and elevations from the sound source. Later, this response was practically implemented to find the sound source through the DM placed on the stepper motor that rotates to find the maximum intensity angle and elevation. The process unfolds in three stages, initially establishing the sound direction at a base elevation, followed by successive elevation adjustments to refine the sound source vertical location through comparative intensity analysis. This methodology not only simplifies the architectural complexity but also enhances the precision of localization. Experimental outcomes demonstrate the system capacity to localize sound sources with an accuracy of ±4° at 30 cm and ±7° at 60 cm distance from the sound source, exhibiting a significant advancement in SSL technology. The proposed single-microphone system, with its reduced complexity and heightened accuracy, presents new prospects for SSL applications, especially in scenarios demanding nuanced human–robot interactions.