Speech analysis system

Abstract

Abstract 1,154,129. Speech recognition. INTERNATIONAL BUSINESS MACHINES CORP. 20 Dec., 1967 [29 Dec., 1966], No. 57991/67. Heading G4R. In speech analysing apparatus, harmonics and the fundamental are detected, detection of the latter controlling means providing signals indicating the time of occurrence of each harmonic. A speech waveform is fed to a pre-amplifier PA having automatic gain control 26, the high, middle (viz. 250-3000 c/s.) and low frequencies being routed to a fricative selector FS, harmonic locator HL and envelope peak detector EPD respectively. In the ease of voiced sound, the detector EPD (which responds to the fundamental) starts a scan ring SCR and a time base ring TBR, after delays. The scan ring SCR distributes the pulses from the harmonic locator HL (presence of a particular harmonic being indicated by presence of a pulse at a corresponding time) to integrating pulse shapers (having a threshold) IPS2-IPS8, the digital outputs from which are set into rows 2-8 of a storage matrix SM, at column positions successively selected by the time base ring TBR. On the other hand, in the case of fricative sound, an integrating pulse shaper IPS 1, fed from the fricative selector FS, starts the time base ring TBR, after a delay, to set successive values of the output of IPS1 into row 1 of the storage matrix SM. The harmonic locator HL consists of a peak detector feeding a univibrator (to produce standard pulses). The delays in activation of the rings are to prevent a pulse from the harmonic locator HL representing the fundamental from being used.

Inventors

• 👤 Genung L Clapper

Bibliographic Details