JPS645250A - Howling prevention circuit for loudspeaker system telephone set - Google Patents

Howling prevention circuit for loudspeaker system telephone set

Info

Publication number
JPS645250A
JPS645250A JP16149087A JP16149087A JPS645250A JP S645250 A JPS645250 A JP S645250A JP 16149087 A JP16149087 A JP 16149087A JP 16149087 A JP16149087 A JP 16149087A JP S645250 A JPS645250 A JP S645250A
Authority
JP
Japan
Prior art keywords
signal
band
echo
frequency component
canceller circuit
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.)
Pending
Application number
JP16149087A
Other languages
Japanese (ja)
Inventor
Yoshio Ito
Ryoichi Miyamoto
Toshimichi Arima
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.)
Oki Electric Industry Co Ltd
Original Assignee
Oki Electric Industry Co Ltd
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 Oki Electric Industry Co Ltd filed Critical Oki Electric Industry Co Ltd
Priority to JP16149087A priority Critical patent/JPS645250A/en
Publication of JPS645250A publication Critical patent/JPS645250A/en
Pending legal-status Critical Current

Links

Landscapes

  • Circuit For Audible Band Transducer (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

PURPOSE:To realize a loudspeaker system telephone set with excellent talking quality by suppressing echo by a 1st echo canceller circuit based on a signal at a band being a half the voice band and using a 2nd echo canceller circuit so as to suppress the echo based on the signal of the remaining band. CONSTITUTION:The voice signal is separated into a 1st band (low frequency component) signal s1(k) and a 2nd band (high frequency component) signal s2(k) at a 1st band separation filter 41. Moreover, the high frequency component s2(k) is added to a pseudo echo signal in the 2nd echo canceller circuit. The pseudo echo signal is obtained by suplying the reception signal high frequency component r2(k) to the 2nd echo canceller circuit 53. The low frequency component s1(k) of the transmission signal is inputted the 1st echo canceller circuit 51 to generate a pseudo echo signal and added to the 1st band signal r1(k) separated by the 2nd band separation filter 45. Thus, the gain of the entire voice band is suppressed to prevent production of howling.
JP16149087A 1987-06-29 1987-06-29 Howling prevention circuit for loudspeaker system telephone set Pending JPS645250A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16149087A JPS645250A (en) 1987-06-29 1987-06-29 Howling prevention circuit for loudspeaker system telephone set

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16149087A JPS645250A (en) 1987-06-29 1987-06-29 Howling prevention circuit for loudspeaker system telephone set

Publications (1)

Publication Number Publication Date
JPS645250A true JPS645250A (en) 1989-01-10

Family

ID=15736064

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16149087A Pending JPS645250A (en) 1987-06-29 1987-06-29 Howling prevention circuit for loudspeaker system telephone set

Country Status (1)

Country Link
JP (1) JPS645250A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0555961A (en) * 1991-08-27 1993-03-05 Aiphone Co Ltd Loud-speaker simultaneous speech system using frequency division
US5414763A (en) * 1991-04-09 1995-05-09 Canon Kabushiki Kaisha Apparatus and method for providing echo suppression to a plurality of telephones
US6510224B1 (en) 1999-05-20 2003-01-21 Telefonaktiebolaget L M Ericsson Enhancement of near-end voice signals in an echo suppression system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5414763A (en) * 1991-04-09 1995-05-09 Canon Kabushiki Kaisha Apparatus and method for providing echo suppression to a plurality of telephones
JPH0555961A (en) * 1991-08-27 1993-03-05 Aiphone Co Ltd Loud-speaker simultaneous speech system using frequency division
US6510224B1 (en) 1999-05-20 2003-01-21 Telefonaktiebolaget L M Ericsson Enhancement of near-end voice signals in an echo suppression system

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