1
Steven L Potts, Hong Wang, Wendi Beth Rabiner, Peter L Chu: Locating an audio source. Polycom, Wong Cabello Lutsch Rutherford & Brucculeri L, July 15, 2003: US06593956 (232 worldwide citation)

A system, such as a video conferencing system, is provided which includes an image pickup device, an audio pickup device, and an audio source locator. The image pickup device generates image signals representative of an image, while the audio pickup device generates audio signals representative of s ...


2
Brant M Helf, Peter L Chu: Reduction of background noise for speech enhancement. PictureTel Corporation, Fish & Richardson P C, August 27, 1996: US05550924 (125 worldwide citation)

Properties of human audio perception are used to perform spectral and time masking to reduce perceived loudness of noise added to the speech signal. A signal is divided temporally into blocks which are then passed through notch filters to remove narrow frequency band components of the noise. Each bl ...


3
Peter L Chu: Adaptive acoustic echo canceller having means for reducing or eliminating echo in a plurality of signal bandwidths. PictureTel Corporation, Hale and Dorr, April 19, 1994: US05305307 (114 worldwide citation)

An echo cancelling device for reducing acoustic feedback between a loudspeaker and microphone in a full duplex communication system such as a telephone conferencing system. The device includes a whitening filter which flattens the microphone signal's spectrum and reduces its auto-correlation. A firs ...


4
Peter L Chu, Hong Wang: Method and apparatus for localization of an acoustic source. PictureTel Corporation, Fish & Richardson P C, July 7, 1998: US05778082 (103 worldwide citation)

An acoustic signal processing method and system using a pair of spatially separated microphones to obtain the direction or location of speech or other acoustic signals from a common sound source is disclosed. The invention includes a method and apparatus for processing the acoustic signals by determ ...


5
Peter L Chu: Method and apparatus for estimating the level of acoustic feedback between a loudspeaker and microphone. PictureTel Corporation, Fish & Richardson, November 16, 1993: US05263019 (95 worldwide citation)

An improved echo cancelling device for reducing the effects of acoustic feedback between a loudspeaker and microphone in a communication system. The device includes an adjustable filter for receiving a loudspeaker signal and generating in response thereto an echo estimation signal. The device subtra ...


6
Peter L Chu: Method and apparatus for steerable and endfire superdirective microphone arrays with reduced analog-to-digital converter and computational requirements. PictureTel Corporation, Fish & Richardson P C, February 3, 1998: US05715319 (70 worldwide citation)

An end fire microphone array having reduced analog-to-digital converter requirements is disclosed. Analog filters are used to band-limit at least two secondary microphone elements which are spaced from a primary microphone element a distance respective of their band limited outputs. The band-limited ...


7
Peter L Chu, Michael Kenoyer, Richard Washington: System and method for computing a location of an acoustic source. Polycom, Wong Cabello Lutsch Rutherford & Brucculeri, June 28, 2005: US06912178 (43 worldwide citation)

In accordance with the present invention, a system and method for computing a location of an acoustic source is disclosed. The method includes steps of processing a plurality of microphone signals in frequency space to search a plurality of candidate acoustic source locations for a maximum normalize ...


8
Jinwei Feng, Yibo Liu, Xiangdong Wang, Peter L Chu: Videoconferencing system having adjunct camera for auto-framing and tracking. Polycom, Wong Cabello Lutsch Rutherford & Brucculeri, September 23, 2014: US08842161 (16 worldwide citation)

A videoconference apparatus and method coordinates a stationary view obtained with a stationary camera to an adjustable view obtained with an adjustable camera. The stationary camera can be a web camera, while the adjustable camera can be a pan-tilt-zoom camera. As the stationary camera obtains vide ...


9
Peter L Chu, Michael Kenoyer, Richard Washington: Videoconferencing system with horizontal and vertical microphone arrays. Polycom, Wong Cabello Lutsch Rutherford & Brucculeri, July 26, 2005: US06922206 (14 worldwide citation)

A system and method for acoustic source location using a horizontal and vertical microphone array. Tilt sensors are provided within each array to allow full determination of the tilt of each array. Based on the acoustic source location results, an image capture device may be maneuvered to focus in t ...


10
Peter L Chu: Acoustic echo canceller clock compensation. Polycom, Wong Cabello Lutsch Rutherford & Brucculeri L, November 27, 2012: US08320554 (13 worldwide citation)

A conferencing endpoint uses acoustic echo cancellation with clock compensation. Receiving far-end audio to be output by a local loudspeaker, the endpoint performs acoustic echo cancellation so that the near-end audio capture by a microphone will lack echo of the far-end audio output from the loudsp ...