Abstract: A system and method for directional sound sensing directs an optical sensing beam to an object of interest having a rough surface that vibrates acoustically. The light is reflected thereby and scattered as a speckle pattern that includes multiple speckles having a random distribution of phase offsets. A detector array having multiple detector elements receives and detects the speckle pattern and produces signals that are linearly proportional to phase modulation of the speckles. A summer receives signals from at least two of the detector elements that are offset at different phases and sums the received signals to generate a non-vanishing signal representative of an acoustic signal.

Abstract: An optical pin-point microphone has a light source for directing a sensing beam to an object of interest so as to be reflected thereby as a reflected signal beam, a detector having multiple detector elements for receiving the reflected signal beam, and a summer for receiving signals from at least two of the detector elements and detecting, rectifying, amplifying and summing the received signals to generate a non-vanishing signal representative of an acoustic signal.