Patents Assigned to Macrowave Technology Corporation
  • Patent number: 4821326
    Abstract: A non-audible speech generation apparatus and method for producing non-audible speech signals which includes an ultrasonic transducer or vibrator for projecting a series of glottal shaped ultrasonic pulses to the vocal track of a speaker. The glottal pulses, in the approximate frequency spectrum extending from fifteen kilohertz to one hundred five kilohertz, contain harmonics of approximately 30 times the frequency of the acoustical harmonics generated by the vocal cords, but which may nevertheless be amplitude modulated to produce non-audible speech by the speaker's silently mouthing of words. The ultrasonic speech is then received by an ultrasonic detector disposed outside of the speaker's mouth and electrically communicated to a translation device which down converts the ultrasonic signals to corresponding signals in the audible frequency range and synthesizes the signals into artificial speech.
    Type: Grant
    Filed: November 16, 1987
    Date of Patent: April 11, 1989
    Assignee: Macrowave Technology Corporation
    Inventor: Norman MacLeod