CA2110031A1 - Digital Sound Level Control Apparatus - Google Patents

Digital Sound Level Control Apparatus

Info

Publication number
CA2110031A1
CA2110031A1 CA2110031A CA2110031A CA2110031A1 CA 2110031 A1 CA2110031 A1 CA 2110031A1 CA 2110031 A CA2110031 A CA 2110031A CA 2110031 A CA2110031 A CA 2110031A CA 2110031 A1 CA2110031 A1 CA 2110031A1
Authority
CA
Canada
Prior art keywords
circuit
signal
level
level signal
sound level
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
CA2110031A
Other languages
French (fr)
Other versions
CA2110031C (en
Inventor
Toshio Honda
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.)
NEC Corp
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of CA2110031A1 publication Critical patent/CA2110031A1/en
Application granted granted Critical
Publication of CA2110031C publication Critical patent/CA2110031C/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
    • H04M9/002—Arrangements for interconnection not involving centralised switching with subscriber controlled access to a line, i.e. key telephone systems
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G7/00—Volume compression or expansion in amplifiers
    • H03G7/007—Volume compression or expansion in amplifiers of digital or coded signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/002—Arrangements for interconnection not involving centralised switching with subscriber controlled access to a line, i.e. key telephone systems
    • H04M9/008—Multiplex systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M3/00—Automatic or semi-automatic exchanges
    • H04M3/40—Applications of speech amplifiers

Abstract

A digital sound level control apparatus for adjusting the reception sound level from all telephone circuits to a substantially fixed level comprises a region discrimination circuit for discriminating PCM data input from a PCM
conversion section, the data having a segment code for compressing and decompressing a digital audio signal, including an intrinsic variation signal, abasic normalization level signal, and a coding threshold value; a multiplicationcircuit for outputting an input level signal of 12 bits, an addition circuit; a register for holding a pad multiplication value corresponding to a reception circuit; another multiplication circuit for multiplying the input level signal by the pad multiplication value to output an output level signal for outputting sound of a predetermined sound level; and a comparison region discrimination circuit, a subtraction circuit, a division circuit, and a register for regenerating an 8-bit digital signal from the output level signal.
CA002110031A 1992-11-26 1993-11-25 Digital sound level control apparatus Expired - Fee Related CA2110031C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP317030/1992 1992-11-26
JP31703092 1992-11-26

Publications (2)

Publication Number Publication Date
CA2110031A1 true CA2110031A1 (en) 1994-05-27
CA2110031C CA2110031C (en) 1997-04-08

Family

ID=18083647

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002110031A Expired - Fee Related CA2110031C (en) 1992-11-26 1993-11-25 Digital sound level control apparatus

Country Status (4)

Country Link
US (1) US5495529A (en)
EP (1) EP0599653B1 (en)
CA (1) CA2110031C (en)
DE (1) DE69326670T2 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5715309A (en) * 1995-03-03 1998-02-03 Advanced Micro Devices, Inc. Conversion of compressed speech codes between attenuated and unattenuated formats
KR100520161B1 (en) * 1998-12-30 2005-11-24 삼성전자주식회사 Coding conversion circuit between local exchange and ISDN key phone system
US8804975B2 (en) 2009-02-13 2014-08-12 University Of Florida Research Foundation, Incorporated Digital sound leveling device and method to reduce the risk of noise induced hearing loss

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3688097A (en) * 1970-05-20 1972-08-29 Bell Telephone Labor Inc Digital attenuator for non-linear pulse code modulation signals
BE792988A (en) * 1971-12-22 1973-04-16 Western Electric Co DIGITAL DEVICE
IT1215464B (en) * 1987-05-07 1990-02-14 Sgs Microelettronica Spa CIRCUIT FOR THE PCM CONVERSION OF AN ANALOG SIGNAL, WITH IMPROVEMENT OF GAIN-TRACKING.
US5025441A (en) * 1987-12-28 1991-06-18 Iwatsu Electric Company, Ltd. Key telephone system
JP3085676B2 (en) * 1989-10-30 2000-09-11 株式会社東芝 Telephone equipment
CA2059883C (en) * 1991-01-24 1995-08-08 Isaku Komuro Key telephone system provided with telephone sets connectable to add-on modules
US5259001A (en) * 1991-12-17 1993-11-02 Motorola, Inc. ADPCM decoder with an integral digital receive gain and method therefor
JP3134455B2 (en) * 1992-01-29 2001-02-13 ソニー株式会社 High efficiency coding apparatus and method

Also Published As

Publication number Publication date
EP0599653A3 (en) 1994-12-07
DE69326670D1 (en) 1999-11-11
EP0599653B1 (en) 1999-10-06
US5495529A (en) 1996-02-27
CA2110031C (en) 1997-04-08
EP0599653A2 (en) 1994-06-01
DE69326670T2 (en) 2000-02-10

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