CA2136366A1 - Background Noise Compensation in a Telephone Network - Google Patents

Background Noise Compensation in a Telephone Network

Info

Publication number
CA2136366A1
CA2136366A1 CA2136366A CA2136366A CA2136366A1 CA 2136366 A1 CA2136366 A1 CA 2136366A1 CA 2136366 A CA2136366 A CA 2136366A CA 2136366 A CA2136366 A CA 2136366A CA 2136366 A1 CA2136366 A1 CA 2136366A1
Authority
CA
Canada
Prior art keywords
speech signal
signal
modified
subband
background noise
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
CA2136366A
Other languages
French (fr)
Other versions
CA2136366C (en
Inventor
Jonathan Brandon Allen
Donald Joseph Youtkus
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.)
University of Colorado Foundation Inc
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 CA2136366A1 publication Critical patent/CA2136366A1/en
Application granted granted Critical
Publication of CA2136366C publication Critical patent/CA2136366C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/02—Constructional features of telephone sets
    • H04M1/19—Arrangements of transmitters, receivers, or complete sets to prevent eavesdropping, to attenuate local noise or to prevent undesired transmission; Mouthpieces or receivers specially adapted therefor
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/62—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission for providing a predistortion of the signal in the transmitter and corresponding correction in the receiver, e.g. for improving the signal/noise ratio
    • H04B1/64—Volume compression or expansion arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M1/00—Substation equipment, e.g. for use by subscribers
    • H04M1/60—Substation equipment, e.g. for use by subscribers including speech amplifiers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/40—Applications of speech amplifiers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
    • G03G7/0006—Cover layers for image-receiving members; Strippable coversheets

Abstract

An automated method for modifying a speech signal in a telephone network by applying a gain factor which is a function of the level of backgroundnoise at a given destination, and transmitting the modified speech signal to thedestination. The gain applied may be a function of both the background noise level and the original speech signal. Either a linear or a non-linear (e.g., compressed) amplification of the original speech signal may be performed, where a compressedamplification results in the higher level portions of the speech signal being amplified by a smaller gain factor than lower level portions. The speech signal may be separated into a plurality of subbands, each resultant subband signal being individually modified in accordance with the present invention. In this case, each subband speech signal is amplified by a gain factor based on a corresponding subband noise signal, generated by separating the background noise signal into acorresponding plurality of subbands. The individual modified subband signals maythen be combined to form the resultant modified speech signal.
CA002136366A 1993-12-29 1994-11-22 Background noise compensation in a telephone network Expired - Fee Related CA2136366C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US175,095 1993-12-29
US08/175,095 US5485515A (en) 1993-12-29 1993-12-29 Background noise compensation in a telephone network

Publications (2)

Publication Number Publication Date
CA2136366A1 true CA2136366A1 (en) 1995-06-30
CA2136366C CA2136366C (en) 1998-07-14

Family

ID=22638863

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002136366A Expired - Fee Related CA2136366C (en) 1993-12-29 1994-11-22 Background noise compensation in a telephone network

Country Status (6)

Country Link
US (2) US5485515A (en)
EP (1) EP0661860B1 (en)
JP (1) JPH07212468A (en)
KR (1) KR100325572B1 (en)
CA (1) CA2136366C (en)
DE (1) DE69432853D1 (en)

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Also Published As

Publication number Publication date
EP0661860B1 (en) 2003-06-25
KR100325572B1 (en) 2002-06-28
EP0661860A3 (en) 1998-01-07
KR950022573A (en) 1995-07-28
JPH07212468A (en) 1995-08-11
DE69432853D1 (en) 2003-07-31
CA2136366C (en) 1998-07-14
US5485515A (en) 1996-01-16
EP0661860A2 (en) 1995-07-05
US5524148A (en) 1996-06-04

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