Eye array dereverberation by corner placement

A new signal processing algorithm accompanied with a novel array structure for sound source localization (SSL) in three-dimensional spaces was presented [Hedayat Alghassi et al., J. Acoust. Soc. Am. 120(5) (2006)]. This methodology has some analogy to the eye. The microphone array’s proper placement is particularly important in enclosed areas, where reverberation is the dominant problem. It will be demonstrated that by placing the eye array’s symmetry axis along the boresight axis of an upper orthogonal trihedral corner in an enclosed area, the adverse effect of early reverberation can be substantially reduced. This enhancement is the consequence of both the retroreflection property of the orthogonal trihedral corners plus the eye array’s insensitivity to back reflections. There is a pseudo-coincidence between the estimation cells and the source direction in the eye array SSL method. Therefore, the majority of the early reflections from the trihedral corner strike the estimation cells in the direction opposite to the sound source, where the sensitivity is lowest. This approach not only reduces the adverse effect of reverberation on the SSL accuracy, but also creates an approximately flat error for all source directions. Experiments confirmed that this method achieves a reasonable accuracy improvement.