CA2052351A1 - Telephone handsfree algorithm - Google Patents
Telephone handsfree algorithmInfo
- 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
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M9/00—Arrangements for interconnection not involving centralised switching
- H04M9/08—Two-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.
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)
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)
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 |
-
1991
- 1991-09-27 CA CA002052351A patent/CA2052351C/en not_active Expired - Lifetime
-
1992
- 1992-09-25 US US08/211,181 patent/US5471528A/en not_active Expired - Lifetime
- 1992-09-25 JP JP05505656A patent/JP3104072B2/en not_active Expired - Fee Related
- 1992-09-25 WO PCT/CA1992/000412 patent/WO1993006679A1/en active IP Right Grant
- 1992-09-25 EP EP92920102A patent/EP0605549B1/en not_active Expired - Lifetime
- 1992-09-25 DE DE69223416T patent/DE69223416T2/en not_active Expired - Lifetime
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 |