Patents by Inventor Charles A. Baldi

Charles A. Baldi 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).

  • Classification of audio signals on a telephone line
    Patent number: 5007000
    Abstract: This telephone solicitation system provides automatic dialing and call-progress detection. Audio signals on the line are analyzed to recognize network operation tones, noise bursts, and speech. A "sample" is the total number of crossings during a 25 millisecond period. A "window" is a sequence of eight samples analyzed for spectral and time patterns.
    Type: Grant
    Filed: June 28, 1989
    Date of Patent: April 9, 1991
    Assignee: International Telesystems Corp.
    Inventor: Charles A. Baldi