Patents by Inventor Thomas B. Schalk

Thomas B. Schalk 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).

  • Patent number: 4831551
    Abstract: Speech recognition is improved using reference pattern templates which have an added noise signal (noise floor) to avoid LPC high-gain synthesizer instability at low signal levels. Also, input signal frames have a length one-half that of reference frames whereby dynamic time warp computation steps are cut almost in half.
    Type: Grant
    Filed: October 13, 1987
    Date of Patent: May 16, 1989
    Assignee: Texas Instruments Incorporated
    Inventors: Thomas B. Schalk, George R. Doddington
  • Patent number: 4712242
    Abstract: Speaker-independent word recognition is performed, based on a small acoustically distinct vocabulary, with minimal hardware requirements. After a simple preconditioning filter, the zero crossing intervals of the input speech are measured and sorted by duration, to provide a rough measure of the frequency distribution within each input frame. The distribution of zero crossing intervals is transformed into a binary feature vector, which is compared with each reference template using a modified Hamming distance measure. A dynamic time warping algorithm is used to permit recognition of various speaker rates, and to economize on the reference template storage requirements. A mask vector with each reference vector on a template is used to ignore insignificant (or speaker-dependent) features of the words detected.
    Type: Grant
    Filed: April 13, 1983
    Date of Patent: December 8, 1987
    Assignee: Texas Instruments Incorporated
    Inventors: Periagaram K. Rajasekaran, George R. Doddington, Thomas B. Schalk