Patents by Inventor Kok Heng Loh

Kok Heng Loh has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method for echo control of a wireless headset
    Patent number: 7647077
    Abstract: The present invention provides a wireless headset with echo control and noise cancellation. The present invention also provides a method with phase reversion for echo control of a wireless headset wherein the wireless headset comprises closely disposed speakers and acoustic sensors. The present invention further provides a method with beamforming for noise cancellation of a wireless headset wherein the wireless headset comprises two separate units disposed in distance, and wherein each unit comprises an acoustic sensor.
    Type: Grant
    Filed: May 29, 2006
    Date of Patent: January 12, 2010
    Assignee: Bitwave Pte Ltd
    Inventors: Siew Kok Hui, Eng Sui Tan, Kok Heng Loh
  • Signal processing apparatus and method for reducing noise and interference in speech communication and speech recognition
    Patent number: 7426464
    Abstract: The present invention uses a method of processing signals in which signals received from an array of sensors are subject to system having a first adaptive filter arranged to enhance a target signal and a second adaptive filter arranged to suppress unwanted signals. The output of the second filter is converted into the frequency domain, and further digital processing is performed in that domain. The invention is further enhanced by incorporating a third adaptive filter in the system and a novel method for performing improved signal processing of audio signals that are suitable for speech communication.
    Type: Grant
    Filed: July 15, 2004
    Date of Patent: September 16, 2008
    Assignee: BITwave Pte Ltd.
    Inventors: Siew Kok Hui, Kok Heng Loh, Boon Teck Pang, Khoon Seong Lim
  • System and apparatus for speech communication and speech recognition
    Patent number: 7346175
    Abstract: A headset system is proposed including a headset unit to be worn by a user and having two or more microphones, and a base unit in wireless communication with the headset. Signals received from the microphones are processed using a first adaptive filter to enhance a target signal, and then divided and supplied to a second adaptive filter arranged to reduce interference signals and a third filter arranged to reduce noise. The outputs of the second and third filters are combined, and are be subject to further a processing in the frequency domain. The results are transmitted to a speech recognition engine.
    Type: Grant
    Filed: July 2, 2002
    Date of Patent: March 18, 2008
    Assignee: Bitwave Private Limited
    Inventors: Siew Kok Hui, Kok Heng Loh, Yean Ming Lau
  • System and apparatus for speech communication and speech recognition
    Publication number: 20040193411
    Abstract: A headset system is proposed including a headset unit to be worn by a user and having two or more microphones, and a base unit in wireless communication with the headset. Signals received from the microphones are processed using a first adaptive filter to enhance a target signal, and then divided and supplied to a second adaptive filter arranged to reduce interference signals and a third filter arranged to reduce noise. The outputs of the second and third filters are combined, and are be subject to further a processing in the frequency domain. The results are transmitted to a speech recognition engine.
    Type: Application
    Filed: February 26, 2004
    Publication date: September 30, 2004
    Inventors: Siew Kok Hui, Kok Heng Loh, Yean Ming Lau