CA2138818A1 - Voice Activity Detection Driven Noise Remediator - Google Patents

Voice Activity Detection Driven Noise Remediator

Info

Publication number
CA2138818A1
CA2138818A1 CA2138818A CA2138818A CA2138818A1 CA 2138818 A1 CA2138818 A1 CA 2138818A1 CA 2138818 A CA2138818 A CA 2138818A CA 2138818 A CA2138818 A CA 2138818A CA 2138818 A1 CA2138818 A1 CA 2138818A1
Authority
CA
Canada
Prior art keywords
speech
signal
voice activity
high pass
remediator
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CA2138818A
Other languages
French (fr)
Other versions
CA2138818C (en
Inventor
Thomas John Janiszewski
Michael Charles Recchione
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AT&T Corp
Original Assignee
American Telephone and Telegraph Co Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by American Telephone and Telegraph Co Inc filed Critical American Telephone and Telegraph Co Inc
Publication of CA2138818A1 publication Critical patent/CA2138818A1/en
Application granted granted Critical
Publication of CA2138818C publication Critical patent/CA2138818C/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J3/00—Time-division multiplex systems
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
    • G10L19/00—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis
    • G10L19/012—Comfort noise or silence coding
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
    • G10L19/00—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis
    • G10L19/04—Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis using predictive techniques
    • G10L19/08—Determination or coding of the excitation function; Determination or coding of the long-term prediction parameters
    • G10L19/12—Determination or coding of the excitation function; Determination or coding of the long-term prediction parameters the excitation function being a code excitation, e.g. in code excited linear prediction [CELP] vocoders
    • G10L19/135—Vector sum excited linear prediction [VSELP]
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
    • G10L21/00—Processing of the speech or voice signal to produce another audible or non-audible signal, e.g. visual or tactile, in order to modify its quality or its intelligibility
    • G10L21/02—Speech enhancement, e.g. noise reduction or echo cancellation
    • G10L21/0208—Noise filtering
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
    • G10L25/00—Speech or voice analysis techniques not restricted to a single one of groups G10L15/00 - G10L21/00
    • G10L25/78—Detection of presence or absence of voice signals
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
    • G10L21/00—Processing of the speech or voice signal to produce another audible or non-audible signal, e.g. visual or tactile, in order to modify its quality or its intelligibility
    • G10L21/02—Speech enhancement, e.g. noise reduction or echo cancellation
    • G10L21/0208—Noise filtering
    • G10L21/0216—Noise filtering characterised by the method used for estimating noise
    • G10L2021/02168—Noise filtering characterised by the method used for estimating noise the estimation exclusively taking place during speech pauses
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS OR SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING; SPEECH OR AUDIO CODING OR DECODING
    • G10L25/00—Speech or voice analysis techniques not restricted to a single one of groups G10L15/00 - G10L21/00
    • G10L25/78—Detection of presence or absence of voice signals
    • G10L2025/783—Detection of presence or absence of voice signals based on threshold decision
    • G10L2025/786—Adaptive threshold

Abstract

A method and apparatus for improving sound quality in a digital cellular radio system receiver. A voice activity detector uses an energy estimate to detect the presence of speech in a received speech signal in a noise environment. When no speech is present the system attenuates the signal and inserts low pass filtered white noise. In addition, a set of high pass filters are used to filter the signal based upon the background noise level. This high pass filtering is applied to the signal regardless of whether speech is present. Thus, a combination of signal attenuation with insertion of low pass filtered white noise during periods of non-speech, along with high pass filtering of the signal, improves sound quality when decoding speech which has been encoded in a noisy environment.
CA002138818A 1994-01-28 1994-12-22 Voice activity detection driven noise remediator Expired - Lifetime CA2138818C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US188,294 1994-01-28
US08/188,294 US5657422A (en) 1994-01-28 1994-01-28 Voice activity detection driven noise remediator

Publications (2)

Publication Number Publication Date
CA2138818A1 true CA2138818A1 (en) 1995-07-29
CA2138818C CA2138818C (en) 1999-05-11

Family

ID=22692567

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002138818A Expired - Lifetime CA2138818C (en) 1994-01-28 1994-12-22 Voice activity detection driven noise remediator

Country Status (7)

Country Link
US (1) US5657422A (en)
EP (2) EP0665530B1 (en)
KR (1) KR100367533B1 (en)
CN (1) CN1132988A (en)
CA (1) CA2138818C (en)
DE (2) DE69533734T2 (en)
RU (1) RU2151430C1 (en)

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Also Published As

Publication number Publication date
KR950035167A (en) 1995-12-30
CA2138818C (en) 1999-05-11
DE69518174D1 (en) 2000-09-07
CN1132988A (en) 1996-10-09
DE69518174T2 (en) 2001-05-31
DE69533734D1 (en) 2004-12-09
EP0665530B1 (en) 2000-08-02
RU2151430C1 (en) 2000-06-20
EP1017042A1 (en) 2000-07-05
RU95101029A (en) 1996-11-10
EP1017042B1 (en) 2004-11-03
DE69533734T2 (en) 2005-11-03
EP0665530A1 (en) 1995-08-02
US5657422A (en) 1997-08-12
KR100367533B1 (en) 2003-04-07

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