Accurate Position Detection of Sound Source by LabView

This paper introduces a method to detect an accurate position, which includes its distance and direction, of a sound source based on a new T- type microphone array having four sound sensors in a LabView development environment. The T-type microphone array consists of three linear microphones in the front side and one in the center of the rear side. Existing linear microphone array types have difficulties in detecting a sound source which exists in the back side of the array. However the type proposed in this paper makes omnidirectional detection possible. The T-type also estimates a source distance by comparing two pressure levels from a front sound sensor and a rear sound sensor respectively. The reduction rate of a sound pressure level is used to calculate the source distance. In general, the direction of a sound source is estimated by calculating the time delay between separate sensors, but the technique proposed in this paper uses both the time delay approach mentioned above and the geometrical method with triangular surveying relations for a higher probability value to obtain the high level accuracy of the direction calculation. Sound-related hardware design requires complex signal processing techniques with a difficulty of desired algorithm verification. In this case, LabView can be used to help intuitive PC-based programming and effective algorithm verification.