CA2177266A1 - Voice Enhancement System and Method - Google Patents

Voice Enhancement System and Method

Info

Publication number
CA2177266A1
CA2177266A1 CA2177266A CA2177266A CA2177266A1 CA 2177266 A1 CA2177266 A1 CA 2177266A1 CA 2177266 A CA2177266 A CA 2177266A CA 2177266 A CA2177266 A CA 2177266A CA 2177266 A1 CA2177266 A1 CA 2177266A1
Authority
CA
Canada
Prior art keywords
voice
output
enhancer
input signal
signal
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
CA2177266A
Other languages
French (fr)
Other versions
CA2177266C (en
Inventor
Helena Shunoi Ho
Michael K. Pratt
Pong C. Lim
Thomas T. Oshidari
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.)
Alcatel Lucent Holdings Inc
Original Assignee
Helena Shunoi Ho
Michael K. Pratt
Pong C. Lim
Thomas T. Oshidari
Dsc Communications Corporation
Alcatel Usa, 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 Helena Shunoi Ho, Michael K. Pratt, Pong C. Lim, Thomas T. Oshidari, Dsc Communications Corporation, Alcatel Usa, Inc. filed Critical Helena Shunoi Ho
Publication of CA2177266A1 publication Critical patent/CA2177266A1/en
Application granted granted Critical
Publication of CA2177266C publication Critical patent/CA2177266C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/40—Applications of speech amplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G5/00—Tone control or bandwidth control in amplifiers
    • H03G5/16—Automatic control
    • H03G5/18—Automatic control in untuned amplifiers
    • H03G5/22—Automatic control in untuned amplifiers having semiconductor devices
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/002—Applications of echo suppressors or cancellers in telephonic connections

Abstract

A telecommunications network (120) is provided with adaptive gain control (AGC) of the voice signals in network (120). Network (120) includes an input (12) for receiving a voice signal, an output (14) for receiving the voice signal, and a coupling between input (12) and output (14) including at least one switch (124) or (126). Network (120) also includes voice enhancer (10) including power averager (18) for measuring and determining the average power of an input signal. Voice enhancer (10) also includes bass band equalizer (16) to attenuate a predetermined portion of the input signal to provide an equalized input signal. From the average power of the input signal is determined a scaling factor from a gain/attenuation look-up table (28). Voice enhancer (10) also includes output scaler (30) coupled to output (14), output scaler (30) scales the equalized input signal with the scaling factor and provides the scaled signal to output (14).
Voice enhancer (10) also includes bass to treble power comparator (20) for detecting tandem enhancement and voice-band data detector (22) which causes enhancer (10) to be disabled appropriately.
CA002177266A 1993-12-02 1994-11-28 Voice enhancement system and method Expired - Fee Related CA2177266C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US161,120 1993-12-02
US08/161,120 US5471527A (en) 1993-12-02 1993-12-02 Voice enhancement system and method
PCT/US1994/013603 WO1995015643A1 (en) 1993-12-02 1994-11-28 Voice enhancement system and method

Publications (2)

Publication Number Publication Date
CA2177266A1 true CA2177266A1 (en) 1995-06-08
CA2177266C CA2177266C (en) 2000-02-01

Family

ID=22579904

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002177266A Expired - Fee Related CA2177266C (en) 1993-12-02 1994-11-28 Voice enhancement system and method

Country Status (14)

Country Link
US (2) US5471527A (en)
EP (1) EP0732024A1 (en)
JP (1) JP3032811B2 (en)
KR (1) KR100268319B1 (en)
CN (1) CN1149373A (en)
AU (2) AU690603B2 (en)
BR (1) BR9408202A (en)
CA (1) CA2177266C (en)
FI (1) FI962305A0 (en)
PL (1) PL175383B1 (en)
RU (1) RU2142675C1 (en)
TW (1) TW321763B (en)
WO (1) WO1995015643A1 (en)
ZA (1) ZA949489B (en)

Families Citing this family (58)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5896449A (en) * 1993-12-02 1999-04-20 Alcatel Usa Sourcing L.P. Voice enhancement system and method
GB2300087B (en) * 1995-04-18 1999-04-28 Ibm Voice processing system and method
US5712954A (en) * 1995-08-23 1998-01-27 Rockwell International Corp. System and method for monitoring audio power level of agent speech in a telephonic switch
FI100840B (en) * 1995-12-12 1998-02-27 Nokia Mobile Phones Ltd Noise attenuator and method for attenuating background noise from noisy speech and a mobile station
US5802164A (en) * 1995-12-22 1998-09-01 At&T Corp Systems and methods for controlling telephone sound enhancement on a per call basis
JPH09321833A (en) * 1996-05-28 1997-12-12 Saitama Nippon Denki Kk Portable telephone set
KR100526216B1 (en) * 1996-11-28 2005-11-04 브리티쉬 텔리커뮤니케이션즈 파블릭 리미티드 캄퍼니 Interactive apparatus
US5995619A (en) * 1996-12-31 1999-11-30 U.S. Philips Corporation Telephony device with compensation for line losses
US6128369A (en) * 1997-05-14 2000-10-03 A.T.&T. Corp. Employing customer premises equipment in communications network maintenance
US5943413A (en) * 1997-06-09 1999-08-24 At&T Corp. Method for selectively routing enhanced calls
FR2765610B1 (en) * 1997-07-04 2003-08-15 Kiekert Ag MOTOR VEHICLE WITH A CLOSING SYSTEM TO BE OPENED OR LOCKED BY REMOTE CONTROL
GB2330961B (en) 1997-11-04 2002-04-24 Nokia Mobile Phones Ltd Automatic Gain Control
EP1062737B8 (en) * 1998-01-15 2009-03-25 Siemens Enterprise Communications GmbH & Co. KG Method for setting up echo suppression devices in communication links with automatic machines
JP4045003B2 (en) * 1998-02-16 2008-02-13 富士通株式会社 Expansion station and its system
US6351529B1 (en) * 1998-04-27 2002-02-26 3Com Corporation Method and system for automatic gain control with adaptive table lookup
US6188763B1 (en) 1998-05-29 2001-02-13 Westell Technologies, Inc. Signal processing unit for network interface unit
US6263074B1 (en) * 1998-06-19 2001-07-17 Lucent Technologies, Inc. User programmable station set bass and treble control
US7181297B1 (en) 1999-09-28 2007-02-20 Sound Id System and method for delivering customized audio data
US6545562B2 (en) * 2001-02-09 2003-04-08 Adc Telecommunications, Inc. Plug connector for cable television network and method of use
US6944474B2 (en) * 2001-09-20 2005-09-13 Sound Id Sound enhancement for mobile phones and other products producing personalized audio for users
US20030168235A1 (en) * 2002-03-07 2003-09-11 Todd Loeffelholz EMI shielded module
US20030230921A1 (en) * 2002-05-10 2003-12-18 George Gifeisman Back support and a device provided therewith
US7155385B2 (en) * 2002-05-16 2006-12-26 Comerica Bank, As Administrative Agent Automatic gain control for adjusting gain during non-speech portions
US6759005B2 (en) * 2002-07-23 2004-07-06 Heraeus, Inc. Fabrication of B/C/N/O/Si doped sputtering targets
US20040105219A1 (en) * 2002-12-03 2004-06-03 Mcclellan Terry E. Chassis for housing telecommunications components
US8249861B2 (en) * 2005-04-20 2012-08-21 Qnx Software Systems Limited High frequency compression integration
US8086451B2 (en) 2005-04-20 2011-12-27 Qnx Software Systems Co. System for improving speech intelligibility through high frequency compression
US7415372B2 (en) 2005-08-26 2008-08-19 Step Communications Corporation Method and apparatus for improving noise discrimination in multiple sensor pairs
US20070047742A1 (en) * 2005-08-26 2007-03-01 Step Communications Corporation, A Nevada Corporation Method and system for enhancing regional sensitivity noise discrimination
US20070047743A1 (en) * 2005-08-26 2007-03-01 Step Communications Corporation, A Nevada Corporation Method and apparatus for improving noise discrimination using enhanced phase difference value
US7619563B2 (en) 2005-08-26 2009-11-17 Step Communications Corporation Beam former using phase difference enhancement
US7472041B2 (en) * 2005-08-26 2008-12-30 Step Communications Corporation Method and apparatus for accommodating device and/or signal mismatch in a sensor array
US20070050441A1 (en) * 2005-08-26 2007-03-01 Step Communications Corporation,A Nevada Corporati Method and apparatus for improving noise discrimination using attenuation factor
US7436188B2 (en) * 2005-08-26 2008-10-14 Step Communications Corporation System and method for improving time domain processed sensor signals
US7864717B2 (en) * 2006-01-09 2011-01-04 Flextronics Automotive Inc. Modem for communicating data over a voice channel of a communications system
US8195454B2 (en) 2007-02-26 2012-06-05 Dolby Laboratories Licensing Corporation Speech enhancement in entertainment audio
US20090010453A1 (en) * 2007-07-02 2009-01-08 Motorola, Inc. Intelligent gradient noise reduction system
US8374851B2 (en) * 2007-07-30 2013-02-12 Texas Instruments Incorporated Voice activity detector and method
EP2232700B1 (en) 2007-12-21 2014-08-13 Dts Llc System for adjusting perceived loudness of audio signals
CN101360351B (en) * 2008-06-03 2012-01-18 无锡友达电子有限公司 Low pass integrated circuit fulfilling mute function by twin span cascade
KR20100024659A (en) * 2008-08-26 2010-03-08 주식회사 팬택 Method and apparatus for controlling audio out, and mobile terminal system applied thereof
CN101741965B (en) * 2008-11-27 2012-10-03 博通集成电路（上海）有限公司 Method for attenuating input signal and noise suppressing device
CN101789797A (en) * 2009-01-22 2010-07-28 浙江安迪信信息技术有限公司 Wireless communication anti-interference system
CN101859568B (en) * 2009-04-10 2012-05-30 比亚迪股份有限公司 Method and device for eliminating voice background noise
US8538042B2 (en) 2009-08-11 2013-09-17 Dts Llc System for increasing perceived loudness of speakers
US8204742B2 (en) 2009-09-14 2012-06-19 Srs Labs, Inc. System for processing an audio signal to enhance speech intelligibility
US8284042B2 (en) * 2009-09-28 2012-10-09 Ford Global Technologies, Llc System and method of vehicle passenger detection for rear seating rows
GB2476043B (en) * 2009-12-08 2016-10-26 Skype Decoding speech signals
KR102060208B1 (en) 2011-07-29 2019-12-27 디티에스 엘엘씨 Adaptive voice intelligibility processor
US9312829B2 (en) 2012-04-12 2016-04-12 Dts Llc System for adjusting loudness of audio signals in real time
US9031838B1 (en) * 2013-07-15 2015-05-12 Vail Systems, Inc. Method and apparatus for voice clarity and speech intelligibility detection and correction
US10986454B2 (en) 2014-01-06 2021-04-20 Alpine Electronics of Silicon Valley, Inc. Sound normalization and frequency remapping using haptic feedback
US8767996B1 (en) 2014-01-06 2014-07-01 Alpine Electronics of Silicon Valley, Inc. Methods and devices for reproducing audio signals with a haptic apparatus on acoustic headphones
US8977376B1 (en) 2014-01-06 2015-03-10 Alpine Electronics of Silicon Valley, Inc. Reproducing audio signals with a haptic apparatus on acoustic headphones and their calibration and measurement
KR102270628B1 (en) 2015-02-09 2021-06-30 엘지전자 주식회사 Refrigerator
US9691413B2 (en) * 2015-10-06 2017-06-27 Microsoft Technology Licensing, Llc Identifying sound from a source of interest based on multiple audio feeds
EA038803B1 (en) * 2017-12-25 2021-10-21 Федеральное государственное унитарное предприятие "Всероссийский научно-исследовательский институт автоматики им. Н.Л. Духова" Method for the adaptive digital filtering of impulse noise and filter for the implementation thereof
RU2702258C1 (en) * 2018-06-26 2019-10-07 Общество с ограниченной ответственностью "РВ-СИСТЕМС" (ООО "РВ-СИСТЕМС") Orthogonal frequency multiplexing method and its implementing device

Family Cites Families (298)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL16990C (en) * 1923-04-30
USRE19305E (en) * 1929-07-17 1934-09-04 Negative impedance repeater
US1844424A (en) * 1930-11-04 1932-02-09 Bell Telephone Labor Inc Long distance telephone transmission
US1968460A (en) * 1932-12-29 1934-07-31 Bell Telephone Labor Inc Noise suppression circuit
US2045300A (en) * 1934-05-31 1936-06-23 Rca Corp Radio receiving system
BE415500A (en) * 1935-05-16
US2151091A (en) * 1935-10-30 1939-03-21 Bell Telephone Labor Inc Signal transmission
US2167011A (en) * 1936-01-13 1939-07-25 Philips Nv Receiving circuit
US2102138A (en) * 1936-02-21 1937-12-14 Bell Telephone Labor Inc Transmission system
US2098350A (en) * 1936-07-02 1937-11-09 American Telephone & Telegraph Control of signaling circuits
US2144565A (en) * 1936-11-30 1939-01-17 Magnavox Company Inc Volume control for electrical sound reproducer
US2134059A (en) * 1937-03-15 1938-10-25 Rca Corp Loudspeaker circuits
US2173426A (en) * 1937-08-30 1939-09-19 Gen Radio Co Electric system
US2154579A (en) * 1937-11-20 1939-04-18 American Telephone & Telegraph Telephone conference circuit
US2190318A (en) * 1938-04-21 1940-02-13 Rca Corp Damping system
US2170941A (en) * 1938-09-15 1939-08-29 Bell Telephone Labor Inc Transmission control in signaling systems
US2209667A (en) * 1939-05-13 1940-07-30 Bell Telephone Labor Inc Control of transmission in two-way signaling systems
US2206146A (en) * 1939-05-27 1940-07-02 Bell Telephone Labor Inc Control of transmission and two-way signaling systems
BE475750A (en) * 1939-10-04
US2248746A (en) * 1940-03-22 1941-07-08 Bell Telephone Labor Inc Signal wave transmission system
US2282465A (en) * 1941-02-27 1942-05-12 Bell Telephone Labor Inc Speech transmission system
US2300415A (en) * 1941-04-26 1942-11-03 Bell Telephone Labor Inc Transmission control
US2350951A (en) * 1941-10-31 1944-06-06 Bell Telephone Labor Inc Electric wave system
US2607860A (en) * 1944-07-12 1952-08-19 Punch Engineering Pty Ltd Frequency selective repeater device
US2606969A (en) * 1946-01-17 1952-08-12 Myron T Smith Method and system for reducing noise in the transmission of electric signals
BE420493A (en) * 1946-01-17
US2606970A (en) * 1946-01-19 1952-08-12 Myron T Smith Method of and system for reducing noise in the transmission of signals
US2606971A (en) * 1946-01-19 1952-08-12 Myron T Smith Method and system for reducing noise in the transmission of electric signals
US2513360A (en) * 1947-01-09 1950-07-04 Nielsen A C Co System for determining the listening habits of wave signal receiver users
BE485032A (en) * 1947-12-22
US2710314A (en) * 1950-06-08 1955-06-07 Tongue Ben Hapgood Wide-band amplifying system
BE507449A (en) * 1950-11-30
BE505815A (en) * 1950-12-27
BE511541A (en) * 1951-05-21
US2766374A (en) * 1951-07-25 1956-10-09 Internat Telementer Corp System and apparatus for determining popularity ratings of different transmitted programs
US2680232A (en) * 1951-09-13 1954-06-01 Revere Camera Co Compensated tone and volume control system
US2759049A (en) * 1951-12-04 1956-08-14 Hermon H Scott Method and system for reducing noise in the transmission of electric signals
US2781417A (en) * 1953-08-07 1957-02-12 George G Bower Telephone transmission system
US2812498A (en) * 1953-09-23 1957-11-05 Cecil T Hall Aural attenuators
US2900609A (en) * 1954-07-27 1959-08-18 Vm Corp Tone compensated loudness control
US2908761A (en) * 1954-10-20 1959-10-13 Bell Telephone Labor Inc Voice pitch determination
GB839975A (en) * 1955-07-28 1960-06-29 Telephone Mfg Co Ltd Improvements in and relating to signal switched telecommunication circuits
US2948778A (en) * 1956-05-07 1960-08-09 Warner W Clements Sound reproducing means
US3045074A (en) * 1958-06-25 1962-07-17 Gylling & Co Ab Amplifier for transmission of speech in two directions
FR1215805A (en) * 1958-11-18 1960-04-20 Cie Ind Des Telephones Improvements to voice-frequency amplifiers
US3114005A (en) * 1959-04-24 1963-12-10 Lenkurt Electric Co Inc Inband signaling system
US3083265A (en) * 1960-02-01 1963-03-26 Itt Conference call circuit
US3183313A (en) * 1960-12-16 1965-05-11 Bell Telephone Labor Inc Echo suppressor operable by a pilot tone
US3102928A (en) * 1960-12-23 1963-09-03 Bell Telephone Labor Inc Vocoder excitation generator
US3083266A (en) * 1961-02-28 1963-03-26 Bell Telephone Labor Inc Vocoder apparatus
FR1313232A (en) * 1961-11-14 1962-12-28 Continuously Variable Level Controller for Powerline Telephone Systems
NL290910A (en) * 1962-03-30
US3145269A (en) * 1962-05-16 1964-08-18 Bell Telephone Labor Inc Control of dynamic range and sensitivity of echo suppressor circuits
US3290442A (en) * 1962-07-11 1966-12-06 Tdk Electronics Co Ltd Noise responsive automatic sound volume controlling system
US3313885A (en) * 1963-05-21 1967-04-11 William R Aiken Combined tone control and volume expander arrangement
NL294443A (en) * 1963-06-21
US3281723A (en) * 1964-02-03 1966-10-25 Fairchild Recording Equipment Dynamic equalizer circuits having a light dependent cell for producing a relatively constant apparent loudness effect
DE1250496B (en) * 1964-02-12
US3360748A (en) * 1964-04-20 1967-12-26 Automatic Elect Lab Double threshold gain regulator for communication systems
US3339027A (en) * 1964-10-07 1967-08-29 Bell Telephone Labor Inc Telephone line range extension circuitry
NL154378B (en) * 1965-01-08 1977-08-15 Frederik Adolf Nauta En Freder SYSTEM AND DEVICE FOR RECORDING LISTENING AND / OR VIEWING DATA.
US3361520A (en) * 1965-02-19 1968-01-02 Garrett Res & Dev Co Process for the preparation of anhydrous aluminum chloride
US3403228A (en) * 1965-03-09 1968-09-24 Bell Telephone Labor Inc Telephone party-line isolation and range extension
US3452282A (en) * 1965-05-03 1969-06-24 Philco Ford Corp Auto radio volume and tone control circuit
US3449518A (en) * 1965-09-15 1969-06-10 Louis W Erath Sound reproduction compensation system
US3428748A (en) * 1965-12-28 1969-02-18 Bell Telephone Labor Inc Vowel detector
US3436488A (en) * 1966-03-17 1969-04-01 Bell Telephone Labor Inc Line circuit for a key telephone system utilizing a single multifunction supervisory relay
US3465104A (en) * 1966-09-09 1969-09-02 Bell Telephone Labor Inc Step-by-step telephone system with range extension
US3493686A (en) * 1966-09-15 1970-02-03 Bell Telephone Labor Inc Telephone switching system serving long customer loops and short customer loops
US3497622A (en) * 1966-10-21 1970-02-24 Zenith Radio Corp Automatic gain control
US3509500A (en) * 1966-12-05 1970-04-28 Avco Corp Automatic digital tuning apparatus
US3530244A (en) * 1967-02-13 1970-09-22 Martin G Reiffin Motional feedback amplifier systems
US3483336A (en) * 1967-04-03 1969-12-09 Lear Siegler Inc Disabling device for the alternating-current path of a two-wire transmission syste
US3496465A (en) * 1967-05-19 1970-02-17 Bell Telephone Labor Inc Fundamental frequency detector
US3497621A (en) * 1967-06-19 1970-02-24 Louis W Erath Audio reproduction system with low frequency compensation
US3508009A (en) * 1967-09-06 1970-04-21 Bell Telephone Labor Inc Range extension circuit
US3684838A (en) * 1968-06-26 1972-08-15 Kahn Res Lab Single channel audio signal transmission system
US3571529A (en) * 1968-09-09 1971-03-16 Zenith Radio Corp Hearing aid with frequency-selective agc
US3617636A (en) * 1968-09-24 1971-11-02 Nippon Electric Co Pitch detection apparatus
US3573402A (en) * 1969-03-25 1971-04-06 Lorain Prod Corp Bidirectional additive amplifier
NL139150B (en) * 1969-05-06 1973-06-15 Nederlanden Staat BIPOLAR TRANSFER.
US3937887A (en) 1969-05-15 1976-02-10 Ben O. Key Acoustic power system
US3821473A (en) 1969-06-20 1974-06-28 J Mullins Sound reproduction system with driven and undriven speakers and motional feedback
BE753495A (en) * 1969-07-21 1970-12-16 Dolby Laboratories Inc PERFECTIONED LIMITER FILTERS FOR NOISE MITIGATION SYSTEMS. (
US3660609A (en) * 1969-08-22 1972-05-02 Communications Systems Corp Subscriber long line extender
US3624302A (en) * 1969-10-29 1971-11-30 Bell Telephone Labor Inc Speech analysis and synthesis by the use of the linear prediction of a speech wave
US3649766A (en) * 1969-12-01 1972-03-14 Bell Telephone Labor Inc Digital speech detection system
US3689704A (en) * 1969-12-17 1972-09-05 Itt Constant current output controlled repeater insertion
US3671676A (en) * 1969-12-17 1972-06-20 Bell Telephone Labor Inc Subscriber loop range extender
US3605042A (en) * 1969-12-22 1971-09-14 Gen Electric Treble control circuit
US3911370A (en) 1970-07-22 1975-10-07 Jerry B Pace Audio frequency amplitude compensator
US3696298A (en) * 1970-07-27 1972-10-03 Kahn Res Lab Audio signal transmission system and method
US3689700A (en) * 1970-09-21 1972-09-05 Lear Siegler Inc Subscriber loop extension unit
JPS4946485B1 (en) 1970-09-30 1974-12-10
US3678416A (en) * 1971-07-26 1972-07-18 Richard S Burwen Dynamic noise filter having means for varying cutoff point
US3699271A (en) * 1970-11-16 1972-10-17 Bell Telephone Labor Inc Speech processor using multiband controlled center clipping
US3689711A (en) * 1971-01-27 1972-09-05 Bell Telephone Labor Inc Call diverter repeater
US3694765A (en) 1971-02-08 1972-09-26 Bell Telephone Labor Inc Signal coupling circuit
JPS5640403B1 (en) 1971-02-10 1981-09-21
GB1390341A (en) 1971-03-12 1975-04-09 Dolby Laboratories Inc Signal compressors and expanders
US3693155A (en) * 1971-03-23 1972-09-19 Nat Telecommunications System Communication system
US3803359A (en) 1971-06-08 1974-04-09 Mc Intosh Labor Inc Equalization system for power amplifier and loudspeaker system
US3706862A (en) * 1971-06-28 1972-12-19 Lorain Prod Corp Amplifier circuit for transmission lines
US3803357A (en) 1971-06-30 1974-04-09 J Sacks Noise filter
US3740476A (en) * 1971-07-09 1973-06-19 Bell Telephone Labor Inc Speech signal pitch detector using prediction error data
US3911371A (en) 1971-07-24 1975-10-07 Sony Corp Signal transmission system
SE348087B (en) 1971-09-20 1972-08-21 Ericsson Telefon Ab L M
US3760108A (en) * 1971-09-30 1973-09-18 Tetrachord Corp Speech diagnostic and therapeutic apparatus including means for measuring the speech intensity and fundamental frequency
US3781481A (en) 1971-09-30 1973-12-25 Stromberg Carlson Corp Amplifier select and control circuit
US3914560A (en) 1971-10-13 1975-10-21 Superior Continental Corp Self-adjusting repeater for voice frequency telephone transmission systems
FR2157143A5 (en) 1971-10-19 1973-06-01 Queffeulou Jean Yves
BE793458A (en) 1971-12-30 1973-06-28 Philips Nv AUTOMATIC EQUALIZATION DEVICE
US3753786A (en) * 1972-03-29 1973-08-21 Gould Inc Method and apparatus for adjusting battery electrolyte concentration
US3900708A (en) 1972-03-31 1975-08-19 Siemens Ag Selective echo suppressor
US3798374A (en) 1972-04-03 1974-03-19 Rene Oliveras Sound reproducing system utilizing motional feedback
US3932712A (en) 1972-06-14 1976-01-13 Stromberg-Carlson Corporation Telephone transmission system
US3890465A (en) 1972-07-11 1975-06-17 Victor Company Of Japan Circuit arrangement for protection of a speaker system
GB1434239A (en) 1972-08-10 1976-05-05 Siemens Ag Echo cancellers
CA982055A (en) 1972-09-11 1976-01-20 Toshiyuki Goto Sound reproducing system
US3806658A (en) 1972-10-30 1974-04-23 Bell Telephone Labor Inc Common controlled equalization system
US3816668A (en) 1972-11-15 1974-06-11 Bell Telephone Labor Inc Arrangement for providing switched range extension
FR2206889A5 (en) 1972-11-16 1974-06-07 Rhone Poulenc Sa
US3916105A (en) 1972-12-04 1975-10-28 Ibm Pitch peak detection using linear prediction
US3784756A (en) 1972-12-15 1974-01-08 Bell Telephone Labor Inc Subscriber loop range extender
US3819866A (en) 1972-12-18 1974-06-25 Bell Telephone Labor Inc Light coupled loop current detector
US3873775A (en) 1973-01-25 1975-03-25 Int Standard Electric Corp Method and an arrangement to indicate deterioration of PCM transmission quality
US3818151A (en) 1973-01-26 1974-06-18 Lorain Prod Corp Method and apparatus for amplifying signal transmission through transmission lines
US3828281A (en) 1973-02-26 1974-08-06 Lorain Prod Corp Impedance simulating circuit for transmission lines
US3934085A (en) 1973-03-28 1976-01-20 Television Research Limited Audio amplifier systems
US3855431A (en) 1973-04-02 1974-12-17 Itt Electronic hybrid amplifier
US3989896A (en) 1973-05-08 1976-11-02 Westinghouse Electric Corporation Method and apparatus for speech identification
US3906491A (en) 1973-05-14 1975-09-16 Federal Sign And Signal Corp Electronic alarm and emergency voice communication system
US3846856A (en) 1973-05-22 1974-11-12 Ying Tu Hsiu Soft mat
JPS5750097B2 (en) 1973-06-06 1982-10-26
US3879583A (en) 1973-08-17 1975-04-22 K Son Corp Reconstruction of telephone dial signals
US3941948A (en) * 1973-11-29 1976-03-02 Brooks Fred A Four-wire interface regulator for long distance trunk circuits
US3946170A (en) 1973-11-29 1976-03-23 Brooks Fred A Self regulating telephone sets
JPS5086915A (en) 1973-11-30 1975-07-12
US3872266A (en) 1973-12-13 1975-03-18 Magnetic Controls Co Telephone monitor circuit
US3911415A (en) 1973-12-18 1975-10-07 Westinghouse Electric Corp Distribution network power line carrier communication system
US3921168A (en) 1974-01-18 1975-11-18 Damon Corp Remote sensing and control system
US3925708A (en) 1974-03-25 1975-12-09 Andrew V Picciochi Safety means for audio speakers
US3903378A (en) 1974-03-27 1975-09-02 Gte Automatic Electric Lab Inc Arrangement for controlling the gain of two-way amplifiers in accordance with loop lengths
US3903366A (en) 1974-04-23 1975-09-02 Us Navy Application of simultaneous voice/unvoice excitation in a channel vocoder
CA1019485A (en) * 1974-06-21 1977-10-18 Sed Systems Ltd. Automatic dialing equipment
US3979557A (en) 1974-07-03 1976-09-07 International Telephone And Telegraph Corporation Speech processor system for pitch period extraction using prediction filters
CH581878A5 (en) 1974-07-22 1976-11-15 Gretag Ag
JPS5325767B2 (en) 1974-09-05 1978-07-28
US4017695A (en) 1974-09-30 1977-04-12 Bell Telephone Laboratories, Incorporated Customer operated gain control circuit
US3918003A (en) 1974-10-29 1975-11-04 Bell Telephone Labor Inc Combined feedback and feedforward automatic gain control
DE2451912C3 (en) 1974-10-31 1980-02-07 Siemens Ag, 1000 Berlin Und 8000 Muenchen Circuit arrangement for equalizing the attenuation curve of a low-frequency cable
US3973087A (en) 1974-12-05 1976-08-03 General Electric Company Signal repeater for power line access data system
US3944723A (en) 1974-12-05 1976-03-16 General Electric Company Station for power line access data system
US3973240A (en) 1974-12-05 1976-08-03 General Electric Company Power line access data system
US4206450A (en) 1974-12-26 1980-06-03 Bowmar Instrument Corporation Fire and intrusion security system
US3967264A (en) 1975-01-31 1976-06-29 Westinghouse Electric Corporation Distribution network power line communication system including addressable interrogation and response repeater
US3942168A (en) 1975-01-31 1976-03-02 Westinghouse Electric Corporation Distribution network power line communication system
US4004096A (en) 1975-02-18 1977-01-18 The United States Of America As Represented By The Secretary Of The Army Process for extracting pitch information
US4007340A (en) 1975-02-25 1977-02-08 Edison Control Corporation Distance-related variable gain amplifier
US4061883A (en) 1975-03-20 1977-12-06 Lorain Products Corporation Repeater for transmission lines of differing lengths
GB1542264A (en) 1975-04-24 1979-03-14 Acoustic Res Int Loudspeaker systems
US4064507A (en) 1975-05-29 1977-12-20 Westinghouse Electric Corporation Noise generator circuit for a security system
US3997724A (en) 1975-06-03 1976-12-14 American Trading And Production Corporation Loudspeaker drive mechanism monitoring assembly
US3959735A (en) 1975-06-16 1976-05-25 Gte Sylvania Incorporated Loudspeaker and amplifier protection circuit
US4074069A (en) 1975-06-18 1978-02-14 Nippon Telegraph & Telephone Public Corporation Method and apparatus for judging voiced and unvoiced conditions of speech signal
US4058676A (en) 1975-07-07 1977-11-15 International Communication Sciences Speech analysis and synthesis system
US4004102A (en) 1975-08-08 1977-01-18 Bell Telephone Laboratories, Incorporated Automatic impedance modification of transmission lines
US3991370A (en) 1975-10-03 1976-11-09 John Pate Peak limiter
US4217661A (en) 1975-10-14 1980-08-12 Kahn Leonard R Audio signal transmission system and method incorporating automatic frequency correction
US4087654A (en) 1975-11-28 1978-05-02 Bell Telephone Laboratories, Incorporated Echo canceller for two-wire full duplex data transmission
US4067008A (en) 1975-12-29 1978-01-03 Denver Fire Reporter & Protective Co., Inc. Multiplex interrogation system using pulses
US4046960A (en) 1975-12-31 1977-09-06 Veale John R Audio fidelity frequency equalizer system
JPS52125251A (en) 1976-02-23 1977-10-20 Bio Communication Res Electric filter and method of designing same
US4051331A (en) 1976-03-29 1977-09-27 Brigham Young University Speech coding hearing aid system utilizing formant frequency transformation
US4061874A (en) 1976-06-03 1977-12-06 Fricke J P System for reproducing sound information
US4027259A (en) 1976-06-14 1977-05-31 Gte Automatic Electric Laboratories Incorporated Line equalizer with differentially controlled complementary constant resistance networks
US4049928A (en) 1976-06-30 1977-09-20 Northern Telecom Limited Self-adjusting voice frequency repeater
US4141006A (en) 1976-07-14 1979-02-20 Braxton Kenneth J Security system for centralized monitoring and selective reporting of remote alarm conditions
US4135590A (en) 1976-07-26 1979-01-23 Gaulder Clifford F Noise suppressor system
US4074087A (en) * 1976-08-16 1978-02-14 Bell Telephone Laboratories, Incorporated Bidirectional voice frequency repeater
US4028496A (en) 1976-08-17 1977-06-07 Bell Telephone Laboratories, Incorporated Digital speech detector
US4143325A (en) 1976-08-20 1979-03-06 Kahn Leonard R Constant amplitude interference squelch system
JPS583601B2 (en) 1976-09-27 1983-01-22 株式会社日立製作所 speaker protection circuit
US4072830A (en) 1976-10-04 1978-02-07 Bell Telephone Laboratories, Incorporated Variable phase shifter for adaptive echo cancellers
US4076959A (en) 1976-10-08 1978-02-28 General Motors Corporation Volume, tone and balance control for multi-channel audio systems
US4056688A (en) 1976-11-11 1977-11-01 Bell Telephone Laboratories, Incorporated Telephone range extender with gain
US4092493A (en) 1976-11-30 1978-05-30 Bell Telephone Laboratories, Incorporated Speech recognition system
US4107460A (en) 1976-12-06 1978-08-15 Threshold Technology, Inc. Apparatus for recognizing words from among continuous speech
US4054941A (en) 1976-12-22 1977-10-18 Bell Telephone Laboratories, Incorporated Range extender with gain
FR2377734A1 (en) 1977-01-17 1978-08-11 Trt Telecom Radio Electr DIGITAL ECHO CANCELER FOR MODEM FOR DATA TRANSMISSION BY MODULATION OF A CARRIER
US4123711A (en) 1977-01-24 1978-10-31 Canadian Patents And Development Limited Synchronized compressor and expander voice processing system for radio telephone
JPS5394160A (en) 1977-01-28 1978-08-17 Pioneer Electronic Corp Muutuning circuit
US4100543A (en) 1977-02-04 1978-07-11 Napco Security Systems, Inc. Audible alarm apparatus particularly adaptable for use with fire and theft security systems
US4178472A (en) 1977-02-21 1979-12-11 Hiroyasu Funakubo Voiced instruction identification system
JPS53105303A (en) 1977-02-25 1978-09-13 Hitachi Ltd Preprocessing system for audio recognition
JPS53117363A (en) 1977-03-24 1978-10-13 Toshiba Corp Modulator
CA1112385A (en) 1977-04-13 1981-11-10 Bloomfield J. Warman Compensation of transmission losses in a telephone system
US4167653A (en) 1977-04-15 1979-09-11 Nippon Electric Company, Ltd. Adaptive speech signal detector
US4210901A (en) 1977-04-25 1980-07-01 Westinghouse Electric Corp. Signal repeater for a distribution network communication system
US4156868A (en) 1977-05-05 1979-05-29 Bell Telephone Laboratories, Incorporated Syntactic word recognizer
FR2404969A1 (en) 1977-10-03 1979-04-27 Cit Alcatel ECHO HALF-SUPPRESSOR FOR A FOUR-WIRE TELEPHONE LINE
US4177356A (en) 1977-10-20 1979-12-04 Dbx Inc. Signal enhancement system
JPS6050092B2 (en) 1977-11-08 1985-11-06 ケイディディ株式会社 Adaptive control echo rejection device
US4132863A (en) 1977-12-20 1979-01-02 Bell Telephone Laboratories, Incorporated Automatic gain and return loss compensating line circuit
US4301329A (en) 1978-01-09 1981-11-17 Nippon Electric Co., Ltd. Speech analysis and synthesis apparatus
US4182930A (en) 1978-03-10 1980-01-08 Dbx Inc. Detection and monitoring device
DE2817156A1 (en) 1978-04-17 1979-10-25 Deutsche Bundespost Echo suppressor for long-distance telephone connections - uses computer to calculate compensation echo signals and adder forming residual echo
US4164626A (en) 1978-05-05 1979-08-14 Motorola, Inc. Pitch detector and method thereof
US4186273A (en) 1978-06-05 1980-01-29 Bose Corporation Stereophonic system having power amplifiers and speakers in a bridge circuit with capacitor connecting junction of speakers to common terminal
US4197429A (en) 1978-07-17 1980-04-08 Bell Telephone Laboratories, Incorporated Gain-adjusting conference circuit
US4207543A (en) 1978-07-18 1980-06-10 Izakson Ilya S Adaptive filter network
DE2833518A1 (en) 1978-07-31 1980-02-21 Siemens Ag Adaptive echo compensator for asynchronous CW system - has frequency corrector containing two multipliers, Hilbert transformer, adder and voltage controlled oscillator
US4230905A (en) 1978-08-18 1980-10-28 Crum Ronald J Stereophonic system with discrete bass channels
IT1115559B (en) 1978-08-29 1986-02-03 Cselt Centro Studi Lab Telecom PROCEDURE AND DEVICE FOR THE NUMERICAL CANCELLATION OF THE ECHO
US4220817A (en) 1978-09-15 1980-09-02 Apt Corporation Audio playback systems
US4277655A (en) 1978-10-16 1981-07-07 Lear Siegler, Inc. Automatic gain repeater
US4229734A (en) 1978-10-26 1980-10-21 Honeywell Inc. Line supervision
US4250489A (en) 1978-10-31 1981-02-10 Westinghouse Electric Corp. Distribution network communication system having branch connected repeaters
US4330686A (en) 1978-12-21 1982-05-18 Stephen Roe Loudspeaker systems
US4296278A (en) 1979-01-05 1981-10-20 Altec Corporation Loudspeaker overload protection circuit
CH644974A5 (en) 1979-02-09 1984-08-31 Blaupunkt Werke Gmbh CIRCUIT ARRANGEMENT FOR AUTOMATICALLY ADJUSTING THE VOLUME AT LEAST ONE SPEAKER TO A NOISE LEVEL FOR RADIO RECEIVERS IN THE SPEAKER LOCATION.
US4351983A (en) 1979-03-05 1982-09-28 International Business Machines Corp. Speech detector with variable threshold
US4268727A (en) 1979-03-14 1981-05-19 International Telephone And Telegraph Corporation Adaptive digital echo cancellation circuit
US4327250A (en) 1979-05-03 1982-04-27 Electro Audio Dynamics Inc. Dynamic speaker equalizer
FR2462070A1 (en) 1979-07-17 1981-02-06 Cit Alcatel DEVICE FOR SUPPLYING A SUBSCRIBER STATION
US4274155A (en) 1979-08-06 1981-06-16 Gte Automatic Electric Laboratories Inc. Multiport conference circuit with multi-frame summing and voice level coding
JPS5636546U (en) 1979-08-31 1981-04-08
US4304968A (en) * 1979-09-24 1981-12-08 Klausner Industries Telephone electronic answering device
US4301330A (en) 1979-09-28 1981-11-17 Zenith Radio Corporation Loudspeaker protection circuit
US4315107A (en) 1979-10-15 1982-02-09 Bell Telephone Laboratories, Incorporated Telephone range extender with gain
US4281218A (en) 1979-10-26 1981-07-28 Bell Telephone Laboratories, Incorporated Speech-nonspeech detector-classifier
US4288871A (en) 1979-11-05 1981-09-08 Bell Telephone Laboratories, Incorporated Digital loop conferencing signal correction arrangement
US4300231A (en) 1979-12-31 1981-11-10 Bell Telephone Laboratories, Incorporated Digital system error correction arrangement
US4277645A (en) 1980-01-25 1981-07-07 Bell Telephone Laboratories, Incorporated Multiple variable threshold speech detector
US4331842A (en) 1980-02-11 1982-05-25 Reliance Electric Company Voice frequency repeater and term sets and other circuits therefor
JPS56132804A (en) 1980-03-22 1981-10-17 Sharp Corp Operational tone quality control circuit
US4352962A (en) 1980-06-27 1982-10-05 Reliance Electric Company Tone responsive disabling circuit
US4354160A (en) 1980-07-01 1982-10-12 Kentrox Industries, Inc. Amplitude equalizer
US4342985A (en) 1980-10-03 1982-08-03 Firecom, Inc. Remote sensing and control system
US4457014A (en) 1980-10-03 1984-06-26 Metme Communications Signal transfer and system utilizing transmission lines
CA1180141A (en) 1980-11-15 1984-12-27 Kenzo Takahashi Echo canceller system
US4592068A (en) 1980-12-23 1986-05-27 International Standard Electric Corporation Repeater for a digital transmission system
DE3120639C2 (en) 1981-05-23 1986-10-23 ANT Nachrichtentechnik GmbH, 7150 Backnang Arrangement for adaptive cancellation of speaker echoes
JPS583430A (en) 1981-06-30 1983-01-10 Nec Corp Suppressing device of detouring signal
US4464545A (en) 1981-07-13 1984-08-07 Bell Telephone Laboratories, Incorporated Echo canceller
US4536888A (en) 1981-08-21 1985-08-20 Plantronics, Inc. Voice communication instrument system with line-powered receiver conditioning circuit
FR2512300A1 (en) 1981-08-25 1983-03-04 Lignes Telegraph Telephon Bidirectional digital data transmission system - uses switching circuit at subscriber equipment to connect variable attenuator controlled from peak power detector memory
ATE15563T1 (en) 1981-09-24 1985-09-15 Gretag Ag METHOD AND DEVICE FOR REDUNDANCY-REDUCING DIGITAL SPEECH PROCESSING.
SE8205839L (en) 1981-10-23 1983-04-24 Western Electric Co echo canceller
SE8205841L (en) 1981-10-23 1983-04-24 Western Electric Co echo canceller
SE8205840L (en) 1981-10-23 1983-04-24 Western Electric Co echo canceller
GB2111354B (en) 1981-11-19 1985-06-19 Standard Telephones Cables Ltd Echo canceller
US4468804A (en) 1982-02-26 1984-08-28 Signatron, Inc. Speech enhancement techniques
US4490843A (en) 1982-06-14 1984-12-25 Bose Corporation Dynamic equalizing
US4644108A (en) 1982-10-27 1987-02-17 International Business Machines Corporation Adaptive sub-band echo suppressor
US4506237A (en) 1982-11-30 1985-03-19 Rockwell International Corporation Adjustable slope equalizer
US4628156A (en) 1982-12-27 1986-12-09 International Business Machines Corporation Canceller trained echo suppressor
US5034984A (en) 1983-02-14 1991-07-23 Bose Corporation Speed-controlled amplifying
US4652703A (en) 1983-03-01 1987-03-24 Racal Data Communications Inc. Digital voice transmission having improved echo suppression
DE3308321A1 (en) 1983-03-09 1984-09-13 Standard Elektrik Lorenz Ag, 7000 Stuttgart Method and circuit arrangement for correcting linear attenuation distortion in transmission channels of telecommunications exchanges
US4542265A (en) 1983-05-20 1985-09-17 Gte Lenkurt Incorporated Echo canceller dynamic range extension
US4535445A (en) 1983-06-16 1985-08-13 At&T Information Systems Conferencing system adaptive signal conditioner
JPS605634A (en) 1983-06-24 1985-01-12 Nec Corp Echo canceller
LU85402A1 (en) 1983-12-01 1984-09-11 Siemens Ag METHOD AND CIRCUIT ARRANGEMENT FOR COMPENSATING CROSS-SPEED AND O. ECHO SIGNALS
US4747132A (en) 1984-04-09 1988-05-24 Matsushita Electric Industrial Co., Ltd. Howling canceller
US4609787A (en) 1984-05-21 1986-09-02 Communications Satellite Corporation Echo canceller with extended frequency range
US4628157A (en) 1984-09-07 1986-12-09 At&T Bell Laboratories Bidirectional adaptive voice frequency repeater
GB8423017D0 (en) 1984-09-12 1984-10-17 Plessey Co Plc Echo canceller
US4731834A (en) 1984-10-01 1988-03-15 American Telephone And Telegraph Company, At&T Bell Laboratories Adaptive filter including signal path compensation
US4682358A (en) 1984-12-04 1987-07-21 American Telephone And Telegraph Company Echo canceller
US4665383A (en) 1985-04-22 1987-05-12 Firecom, Inc. Security system with monitoring and warning circuits
IT1184949B (en) 1985-05-14 1987-10-28 Sip IMPROVEMENT OF BIDIRECTIONAL NUMERIC TRANSMISSION SYSTEMS WITH D ECHO CANCELLATION
US4809338A (en) 1985-07-05 1989-02-28 Harman International Industries, Incorporated Automotive sound system
US4638298A (en) 1985-07-16 1987-01-20 Telautograph Corporation Communication system having message repeating terminals
US4879748A (en) 1985-08-28 1989-11-07 American Telephone And Telegraph Company Parallel processing pitch detector
JPH0746788B2 (en) 1985-11-05 1995-05-17 日本電気株式会社 Automatic track equalizer
US4882749A (en) 1986-01-09 1989-11-21 Harris Semiconductor (Patents) Inc. Control of signal transmission
US4853581A (en) 1986-02-10 1989-08-01 Photo Redux Corp. Radiation-emitting devices
FR2597690B1 (en) 1986-04-22 1988-06-10 Trt Telecom Radio Electr APPARATUS FOR DETECTION AND DISCRIMINATION OF PHASE JUMPS IN A PERIODIC SIGNAL AND APPLICATION TO A TELEPHONE TONE SIGNAL WITH PHASE INVERSIONS.
NL8601712A (en) 1986-07-01 1988-02-01 Koninkl Philips Electronics Nv COMMUNICATION NETWORK, IN PARTICULAR A TELEPHONE NETWORK AND DATA COMMUNICATION NETWORK COMPOSED OF A COLLECTION OF BUTTON UNITS, WHICH FOLLOWS SPECIFIC FACILITIES UNDER DUTIES.
DE3629596A1 (en) 1986-08-30 1988-03-03 Standard Elektrik Lorenz Ag CIRCUIT ARRANGEMENT FOR DECOUPLING THE TRANSFER BRANCHES OF A HANDS-FREE UNIT
US4894820A (en) * 1987-03-24 1990-01-16 Oki Electric Industry Co., Ltd. Double-talk detection in an echo canceller
IT1211194B (en) 1987-07-10 1989-10-12 Olivetti & Co Spa AUTOMATIC DISTORTION MEASUREMENT AND COMPENSATION SYSTEM OF A CONNECTION BETWEEN A TELEPHONE AND A CENTRAL VOICE TREATMENT UNIT
DE3728109C1 (en) 1987-08-22 1989-03-16 Telefonbau & Normalzeit Gmbh Method for voice-controlled attenuation control in telephone transmission circuits
US4879746A (en) 1987-12-30 1989-11-07 Plantronics, Inc. Voice communication link interface apparatus
CA1315356C (en) * 1988-07-20 1993-03-30 Seiji Miyoshi Digital adaptive filter and method of convergence therein
US4969144A (en) 1989-01-03 1990-11-06 Universal Data Systems, Inc. Adaptive passband echo canceller
JP3085676B2 (en) 1989-10-30 2000-09-11 株式会社東芝 Telephone equipment
US5280473A (en) 1990-02-08 1994-01-18 Universal Data Systems, Inc. Modem with echo cancellation
NL9001016A (en) 1990-04-27 1991-11-18 Philips Nv DIGITAL ECHO COMPENSATOR WITH A DOUBLE-VOICE DETECTOR.
JP3158414B2 (en) 1990-06-25 2001-04-23 日本電気株式会社 Echo canceller
US5195132B1 (en) 1990-12-03 1996-03-19 At & T Bell Lab Telephone network speech signal enhancement
US5206902A (en) 1991-04-01 1993-04-27 At&T Bell Laboratories Network signaling arrangement for controlling tandem network functions
DE69123579T2 (en) 1991-09-06 1997-06-12 Ibm Method for adaptive echo cancellation and device for carrying out the method
US5280525A (en) 1991-09-27 1994-01-18 At&T Bell Laboratories Adaptive frequency dependent compensation for telecommunications channels
US5388185A (en) 1991-09-30 1995-02-07 U S West Advanced Technologies, Inc. System for adaptive processing of telephone voice signals
US5317596A (en) 1992-12-01 1994-05-31 The Board Of Trustees Of The Leland Stanford, Junior University Method and apparatus for echo cancellation with discrete multitone modulation
US5351031A (en) * 1993-02-16 1994-09-27 The Grass Valley Group, Inc. Non-linear slew rate limiter

Also Published As

Publication number Publication date
CA2177266C (en) 2000-02-01
AU1101895A (en) 1995-06-19
US5592545A (en) 1997-01-07
KR960706738A (en) 1996-12-09
BR9408202A (en) 1997-08-26
WO1995015643A1 (en) 1995-06-08
RU2142675C1 (en) 1999-12-10
KR100268319B1 (en) 2000-10-16
US5471527A (en) 1995-11-28
CN1149373A (en) 1997-05-07
JPH09506220A (en) 1997-06-17
PL175383B1 (en) 1998-12-31
FI962305A (en) 1996-05-31
EP0732024A1 (en) 1996-09-18
TW321763B (en) 1997-12-01
ZA949489B (en) 1995-08-14
FI962305A0 (en) 1996-05-31
JP3032811B2 (en) 2000-04-17
AU690603B2 (en) 1998-04-30
PL314880A1 (en) 1996-09-30
AU6482298A (en) 1998-07-02

Similar Documents

Publication Publication Date Title
CA2177266A1 (en) Voice Enhancement System and Method
WO1997024858A3 (en) Voice enhancement system and method
EP0299507B1 (en) Electronic telephone terminal having noise suppression function
EP0385782B1 (en) Time dependent, variable amplitude threshold output circuit for frequency variant and frequency invariant signal discrimination
US5267322A (en) Digital automatic gain control with lookahead, adaptive noise floor sensing, and decay boost initialization
SE9500858D0 (en) Arrangement and method relating to speech transmission and a telecommunications system comprising such arrangement
US4560840A (en) Digital handsfree telephone
US5058153A (en) Noise mitigation and mode switching in communications terminals such as telephones
MY131662A (en) Noise reducing method,noise reducing apparatus and telephone set.
CA2117587A1 (en) System for adaptively reducing noise in speech signals
US5838269A (en) System and method for performing automatic gain control with gain scheduling and adjustment at zero crossings for reducing distortion
JPH0750553A (en) Upgrading method for audio signal in communication channel and communication system
JP2586827B2 (en) Receiver
CA2062216A1 (en) Optical-to-electric transducer with extended dynamic range
EP0781029A3 (en) Loudspeaker telephone device comprising a novel noise suppressing circuit
GB2301731A (en) Speakerphone
EP0175375A2 (en) Telephone
CA1108236A (en) Level control circuitry for two way communication system
CA2053124A1 (en) Speech detection circuit
EP0642251A3 (en) Method for the automatic switching of the speech direction and circuit arrangement for implementing the method
TW297193B (en) Voice enhacement system and method
JPH06175693A (en) Voice detection method
JP2808928B2 (en) Background noise power detector
GB2318025A (en) Speakerphone
JPS6420761A (en) Telephone terminal

Legal Events

Date Code Title Description
EEER Examination request
MKLA Lapsed