CA2052351A1 - Telephone handsfree algorithm - Google Patents

Telephone handsfree algorithm

Info

Publication number
CA2052351A1
CA2052351A1 CA2052351A CA2052351A CA2052351A1 CA 2052351 A1 CA2052351 A1 CA 2052351A1 CA 2052351 A CA2052351 A CA 2052351A CA 2052351 A CA2052351 A CA 2052351A CA 2052351 A1 CA2052351 A1 CA 2052351A1
Authority
CA
Canada
Prior art keywords
audio
signals
paths
transmit
speech
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
CA2052351A
Other languages
French (fr)
Other versions
CA2052351C (en
Inventor
Gordon J. Reesor
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.)
Mitel Networks Corp
Original Assignee
Mitel Corp
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 Mitel Corp filed Critical Mitel Corp
Priority to CA002052351A priority Critical patent/CA2052351C/en
Priority to EP92920102A priority patent/EP0605549B1/en
Priority to JP05505656A priority patent/JP3104072B2/en
Priority to PCT/CA1992/000412 priority patent/WO1993006679A1/en
Priority to US08/211,181 priority patent/US5471528A/en
Priority to DE69223416T priority patent/DE69223416T2/en
Publication of CA2052351A1 publication Critical patent/CA2052351A1/en
Application granted granted Critical
Publication of CA2052351C publication Critical patent/CA2052351C/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04MTELEPHONIC COMMUNICATION
    • H04M9/00Arrangements for interconnection not involving centralised switching
    • H04M9/08Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic

Abstract

A handsfree telephone circuit has separate transmit and receive audio paths for connection to a microphone and speaker respectively. The circuit comprises a controllable attenuator in each of said transmit and receive paths, an attenuator control responsive to control signals to set the attenuation level of said attenuators, and a separate monitoring circuit connected to each of said transmit and receive paths for sensing audio signals therein. Each monitoring circuit comprises a filter for band limiting the audio signals, a peak level detector receiving said band limited signals, and a speech detector for distinguishing speech from background noise. A switching comparator compares the outputs of the peak level detectors in the two monitoring circuits and produces directional control signals for said attenuator control means to determine which audio path has control. The circuit is prone to causing a "hollow" effect in the speech due to bandlimiting filtering in the audio paths.
CA002052351A 1991-09-27 1991-09-27 Telephone handsfree algorithm Expired - Lifetime CA2052351C (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
CA002052351A CA2052351C (en) 1991-09-27 1991-09-27 Telephone handsfree algorithm
EP92920102A EP0605549B1 (en) 1991-09-27 1992-09-25 Handsfree telephone apparatus
JP05505656A JP3104072B2 (en) 1991-09-27 1992-09-25 Hands-free telephone
PCT/CA1992/000412 WO1993006679A1 (en) 1991-09-27 1992-09-25 Handsfree telephone apparatus
US08/211,181 US5471528A (en) 1991-09-27 1992-09-25 Voice switched speakerphone with filters having exponential transfer function in the monitoring path
DE69223416T DE69223416T2 (en) 1991-09-27 1992-09-25 HANDS-FREE TELEPHONE

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA002052351A CA2052351C (en) 1991-09-27 1991-09-27 Telephone handsfree algorithm

Publications (2)

Publication Number Publication Date
CA2052351A1 true CA2052351A1 (en) 1993-03-28
CA2052351C CA2052351C (en) 2000-05-23

Family

ID=4148452

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002052351A Expired - Lifetime CA2052351C (en) 1991-09-27 1991-09-27 Telephone handsfree algorithm

Country Status (6)

Country Link
US (1) US5471528A (en)
EP (1) EP0605549B1 (en)
JP (1) JP3104072B2 (en)
CA (1) CA2052351C (en)
DE (1) DE69223416T2 (en)
WO (1) WO1993006679A1 (en)

Families Citing this family (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06216986A (en) * 1993-01-19 1994-08-05 Mitsubishi Electric Corp Hand-free speech circuit
JPH06338934A (en) * 1993-05-25 1994-12-06 Exar Corp Speaker horn with phenomenon driving type control circuit
GB2281680B (en) * 1993-08-27 1998-08-26 Motorola Inc A voice activity detector for an echo suppressor and an echo suppressor
FI108830B (en) * 1993-12-23 2002-03-28 Nokia Corp Method and apparatus for echo suppression in a telephone apparatus
US6768776B1 (en) * 1994-02-04 2004-07-27 Legerity, Inc. Transcoder-codec circuit arrangement and method that supports voice-switched hands-free radio operation
JPH07273840A (en) * 1994-03-25 1995-10-20 Nec Corp Mobile telephone set with voice band control function
JPH07297900A (en) * 1994-04-26 1995-11-10 Mitsubishi Electric Corp Communication equipment taking countermeasure against noise sound
US5668871A (en) * 1994-04-29 1997-09-16 Motorola, Inc. Audio signal processor and method therefor for substantially reducing audio feedback in a cummunication unit
JP2845130B2 (en) * 1994-05-13 1999-01-13 日本電気株式会社 Communication device
JPH0832494A (en) * 1994-07-13 1996-02-02 Mitsubishi Electric Corp Hand-free talking device
JP2600622B2 (en) * 1994-09-22 1997-04-16 日本電気株式会社 Transmission control method of downlink control signal in TDMA mobile communication system
US6041118A (en) * 1994-12-22 2000-03-21 Lucent Technologies Inc. Architecture for telephone set
JPH08204619A (en) * 1995-01-26 1996-08-09 Nec Corp Echo suppressor
US5680450A (en) * 1995-02-24 1997-10-21 Ericsson Inc. Apparatus and method for canceling acoustic echoes including non-linear distortions in loudspeaker telephones
US5636272A (en) * 1995-05-30 1997-06-03 Ericsson Inc. Apparatus amd method for increasing the intelligibility of a loudspeaker output and for echo cancellation in telephones
GB2301731B (en) * 1995-05-31 1998-09-02 Casio Phonemate Inc Speakerphone, speakerphone system and method of operating a speakerphone
US5692042A (en) * 1995-05-31 1997-11-25 Casio Phonemate, Inc. Speakerphone controlled by a comparator with hysteresis
US6175634B1 (en) 1995-08-28 2001-01-16 Intel Corporation Adaptive noise reduction technique for multi-point communication system
US5598466A (en) * 1995-08-28 1997-01-28 Intel Corporation Voice activity detector for half-duplex audio communication system
US5764753A (en) * 1995-09-29 1998-06-09 Crystal Semiconductor Corp. Half-duplex controller
US5867573A (en) * 1996-02-06 1999-02-02 Lucent Technologies Inc. Telephone handset interface with feedback control
US5892823A (en) 1996-03-27 1999-04-06 Hello Direct, Inc. Smart interface technology
US5838787A (en) * 1996-06-27 1998-11-17 Northern Telecom Limited Method and system for controlling echo return loss using a complementary variolosses in transmit path
US5796818A (en) * 1996-08-08 1998-08-18 Northern Telecom Limited Dynamic optimization of handsfree microphone gain
US6978009B1 (en) 1996-08-20 2005-12-20 Legerity, Inc. Microprocessor-controlled full-duplex speakerphone using automatic gain control
US5787165A (en) * 1996-12-13 1998-07-28 Ericsson Inc. Handsfree radiotelephone having dynamic path attenuation control for echo suppression
JP3220979B2 (en) * 1998-01-09 2001-10-22 日本電気株式会社 Voice switch
AUPP999199A0 (en) * 1999-04-28 1999-05-20 Telstra Corporation Limited Apparatus and method for detecting far end speech
SE514793C2 (en) * 1999-05-31 2001-04-23 Ericsson Telefon Ab L M Procedure and system for line level adjustment between networks
US7263074B2 (en) * 1999-12-09 2007-08-28 Broadcom Corporation Voice activity detection based on far-end and near-end statistics
JP3929686B2 (en) * 2000-08-14 2007-06-13 松下電器産業株式会社 Voice switching apparatus and method
US6795547B1 (en) * 2000-08-02 2004-09-21 Conexant Systems, Inc. Full duplex speaker-phone providing increased loop stability
US6836156B2 (en) * 2003-04-25 2004-12-28 Broadcom Corp. High frequency signal peak detector
US8611554B2 (en) * 2008-04-22 2013-12-17 Bose Corporation Hearing assistance apparatus
US8340312B2 (en) 2009-08-04 2012-12-25 Apple Inc. Differential mode noise cancellation with active real-time control for microphone-speaker combinations used in two way audio communications
GB2561021B (en) * 2017-03-30 2019-09-18 Cirrus Logic Int Semiconductor Ltd Apparatus and methods for monitoring a microphone
GB2567018B (en) 2017-09-29 2020-04-01 Cirrus Logic Int Semiconductor Ltd Microphone authentication
US11769510B2 (en) 2017-09-29 2023-09-26 Cirrus Logic Inc. Microphone authentication
KR102425566B1 (en) 2020-08-10 2022-07-26 김태준 Lure For Fish

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3963868A (en) * 1974-06-27 1976-06-15 Stromberg-Carlson Corporation Loudspeaking telephone hysteresis and ambient noise control
US4210872A (en) * 1978-09-08 1980-07-01 American Microsystems, Inc. High pass switched capacitor filter section
US4293820A (en) * 1979-08-23 1981-10-06 Centre De Recherche Industrielle Du Quebec Positive feedback biquad filter
US4315227A (en) * 1979-12-05 1982-02-09 Bell Telephone Laboratories, Incorporated Generalized switched-capacitor active filter
JPS5797262A (en) * 1980-12-09 1982-06-16 Nippon Telegr & Teleph Corp <Ntt> Loud speaker telephone set system
GB2122851B (en) * 1982-06-10 1986-03-19 Standard Telephones Cables Ltd Loudspeaking telephones
US4490582A (en) * 1983-02-18 1984-12-25 At&T Information Systems Inc. Speakerphone control circuit
JPS59193660A (en) * 1983-04-18 1984-11-02 Nec Corp Conference telephone set
GB2161047B (en) * 1984-06-28 1987-09-16 Stc Plc Improvements in telephone instruments
US4608462A (en) * 1984-06-29 1986-08-26 International Standard Electric Corporation Telephone instrument circuit
CA1233925A (en) * 1985-05-10 1988-03-08 Gordon J. Reesor Digital loudspeaking telephone
US4715063A (en) * 1985-08-20 1987-12-22 Motorola, Inc. Speakerphone for radio and landline telephones
EP0290952B1 (en) * 1987-05-15 1992-11-04 Alcatel SEL Aktiengesellschaft Speech control circuitry for a telecommunication terminal
US4879745A (en) * 1988-10-12 1989-11-07 Ibm Corporation Half-duplex speakerphone
FR2641150B1 (en) * 1988-12-28 1991-04-19 Sgs Thomson Microelectronics
DE59008583D1 (en) * 1989-10-18 1995-04-06 Siemens Ag Method for automatic switching of messages and circuit arrangement for carrying out the method.
CA2001277C (en) * 1989-10-24 1994-07-12 Bruce Leigh Townsend Hands free telecommunications apparatus and method
US5058153A (en) * 1989-12-27 1991-10-15 Carew Edward C Noise mitigation and mode switching in communications terminals such as telephones
US5075687A (en) * 1990-09-27 1991-12-24 Advanced Micro Devices, Inc. Echo suppression with both digital and analog variable attenuators

Also Published As

Publication number Publication date
EP0605549A1 (en) 1994-07-13
JPH06510889A (en) 1994-12-01
US5471528A (en) 1995-11-28
DE69223416D1 (en) 1998-01-15
JP3104072B2 (en) 2000-10-30
EP0605549B1 (en) 1997-12-03
CA2052351C (en) 2000-05-23
DE69223416T2 (en) 1998-07-09
WO1993006679A1 (en) 1993-04-01

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Legal Events

Date Code Title Description
EEER Examination request
MKLA Lapsed
MKEC Expiry (correction)

Effective date: 20121202