11
George R Doddington, Enrico Bocchieri: Speaker independent speech recognition method and system. Texas Instruments Incorporated, William E Hiller, N Rhys Merrett, Melvin Sharp, March 13, 1990: US04908865 (44 worldwide citation)

Recognition of sound units is improved by comparing frame-pair feature vectors which helps compensate for context variations in the pronunciation of sound units. A plurality of reference frames are stored of reference feature vectors representing reference words. A linear predictive coder (10) gener ...


12
Bruce G Secrest, George R Doddington: Voice messaging system with pitch tracking based on adaptively filtered LPC residual signal. Texas Instruments Incorporated, William E Hiller, N Rhys Merrett, Melvin Sharp, March 15, 1988: US04731846 (40 worldwide citation)

A voice messaging system, wherein linear predictive coding (LPC) parameters, pitch, and preferably other excitation information is derived from a human voice input, encoded, and transmitted and/or stored, to be called up later to provide a speech output which is nearly identical to the original spee ...


13
Jayant M Naik, Lorin P Netsch, George R Doddington: Voice verification circuit for validating the identity of telephone calling card customers. Texas Instruments Incorporated, Pehr B Jansson, Frank J Kowalski, Leo N Heiting, June 1, 1993: US05216720 (39 worldwide citation)

An apparatus and method for verifying the identity of an unknown user of a telephone calling card service is disclosed which receives identification information corresponding to a valid user of the service, requests the unknown user to speak an authorization phrase without disclosing the authorizati ...


14
George R Doddington, Panos E Papamichalis: Speech analysis/synthesis system with energy normalization and silence suppression. Texas Instruments Incorporated, Kenneth C Hill, James T Comfort, Melvin Sharp, September 22, 1987: US04696040 (37 worldwide citation)

Energy normalization in speech synthesis systems is achieved by a look-ahead adaptive normalization procedure, wherein energy is adaptively tracked, and the adaptive energy-tracking value is used to normalize a much earlier frame's energy value.


15
George R Doddington, P K Rajasekaran, Michael L McMahan, Wallace Anderson: Low cost speech recognition system and method. Texas Instruments Incorporated, James T Comfort, Melvin Sharp, March 20, 1990: US04910784 (31 worldwide citation)

A low cost speech recognition system generates frames of received speech having binary feature components. The received speech frames are compared with reference templates, and error values representing the difference between the received speech and the reference templates are generated. At the end ...


16
Panos E Papamichalis, George R Doddington: Time encoding of LPC roots. Texas Instruments Incorporated, Kenneth C Hill, James T Comfort, Melvin Sharp, November 25, 1986: US04625286 (30 worldwide citation)

Since the formants in human speech move slowly over time, their slow time-varying behavior provides a source of information redundancy which can be used to reduce the required data rate in encoding of speech. In the present invention, speech is encoded by an adaptive tracking procedure, which follow ...


17
Jayant M Naik, Lorin P Netsch, George R Doddington: Voice verification circuit for validating the identity of an unknown person. Texas Instruments Incorporated, L Joy Griebenow, N Rhys Merrett, Melvin Sharp, October 1, 1991: US05054083 (29 worldwide citation)

A speaker verification system receives input speech from a speaker of unknown identity. The speech undergoes linear predictive coding (LPC) analysis and transformation to maximize separability between true speakers and impostors when compared to reference speech parameters which have been similarly ...


18
George R Doddington, Bruce G Secrest: Voice messaging system with unified pitch and voice tracking. Texas Instruments Incorporated, William E Hiller, N Rhys Merrett, Melvin Sharp, September 22, 1987: US04696038 (28 worldwide citation)

This voice messaging system provides an LPC analyzer in combination with a pitch extractor wherein LPC parameters and a residual signal organized in a sequence of speech data frames are provided by the LPC analyzer as an output representative of an analog speech signal. The pitch extractor is operab ...


19
Periagaram K Rajasekaran, George R Doddington: Speaker-independent word recognizer. Texas Instruments Incorporated, William E Hiller, N Rhys Merrett, Melvin Sharp, August 9, 1988: US04763278 (26 worldwide citation)

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 freq ...


20
Periagaram K Rajasekaran, George R Doddington, Thomas B Schalk: Speaker-independent word recognizer. Texas Instruments Incorporated, William E Hiller, N Rhys Merrett, Mel Sharp, December 8, 1987: US04712242 (24 worldwide citation)

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 freq ...