CA2256485A1 - Superdirective microphone arrays - Google Patents

Superdirective microphone arrays

Info

Publication number
CA2256485A1
CA2256485A1 CA002256485A CA2256485A CA2256485A1 CA 2256485 A1 CA2256485 A1 CA 2256485A1 CA 002256485 A CA002256485 A CA 002256485A CA 2256485 A CA2256485 A CA 2256485A CA 2256485 A1 CA2256485 A1 CA 2256485A1
Authority
CA
Canada
Prior art keywords
microphone
band
superdirective
analog
digitized
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
CA002256485A
Other languages
French (fr)
Other versions
CA2256485C (en
Inventor
Peter L. Chu
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.)
Polycom Inc
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 CA2256485A1 publication Critical patent/CA2256485A1/en
Application granted granted Critical
Publication of CA2256485C publication Critical patent/CA2256485C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H04R3/005—Circuits for transducers, loudspeakers or microphones for combining the signals of two or more microphones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2201/00—Details of transducers, loudspeakers or microphones covered by H04R1/00 but not provided for in any of its subgroups
    • H04R2201/40—Details of arrangements for obtaining desired directional characteristic by combining a number of identical transducers covered by H04R1/40 but not provided for in any of its subgroups
    • H04R2201/401—2D or 3D arrays of transducers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2201/00—Details of transducers, loudspeakers or microphones covered by H04R1/00 but not provided for in any of its subgroups
    • H04R2201/40—Details of arrangements for obtaining desired directional characteristic by combining a number of identical transducers covered by H04R1/40 but not provided for in any of its subgroups
    • H04R2201/403—Linear arrays of transducers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2201/00—Details of transducers, loudspeakers or microphones covered by H04R1/00 but not provided for in any of its subgroups
    • H04R2201/40—Details of arrangements for obtaining desired directional characteristic by combining a number of identical transducers covered by H04R1/40 but not provided for in any of its subgroups
    • H04R2201/405—Non-uniform arrays of transducers or a plurality of uniform arrays with different transducer spacing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R25/00—Deaf-aid sets, i.e. electro-acoustic or electro-mechanical hearing aids; Electric tinnitus maskers providing an auditory perception
    • H04R25/40—Arrangements for obtaining a desired directivity characteristic
    • H04R25/407—Circuits for combining signals of a plurality of transducers

Abstract

An end fire microphone array having reduced analog-to-digital converter requirements is disclosed. Analog filters (112, 113, 114) are used to band-limit at least two secondary microphone elements (102, 103, 104) which are spaced from a primary microphone element (101) a distance respective of their band limited outputs. The band-limited secondary microphone signals are digitized by an analog-to-digital converter (120).
A signal processor (130) performs a superdirective analysis of the primary microphone (101) signal and the combined secondary microphone signals (115). A steerable superdirective microphone array is also disclosed in which a plurality of microphones are arranged in a ring. Their outputs are digitized, split into frequency bands, and weighted sums are formed for each of a plurality of directions. A steering control circuit evaluates the relative energy of each directional signal in each band and selects a microphone direction for further processing and output.
CA002256485A 1996-05-30 1997-05-28 Superdirective microphone arrays Expired - Fee Related CA2256485C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US08/657,636 1996-05-30
US08/657,636 US5715319A (en) 1996-05-30 1996-05-30 Method and apparatus for steerable and endfire superdirective microphone arrays with reduced analog-to-digital converter and computational requirements
PCT/US1997/008918 WO1997046048A1 (en) 1996-05-30 1997-05-28 Superdirective microphone arrays

Publications (2)

Publication Number Publication Date
CA2256485A1 true CA2256485A1 (en) 1997-12-04
CA2256485C CA2256485C (en) 2004-02-17

Family

ID=24638007

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002256485A Expired - Fee Related CA2256485C (en) 1996-05-30 1997-05-28 Superdirective microphone arrays

Country Status (5)

Country Link
US (1) US5715319A (en)
EP (1) EP0903056A4 (en)
JP (1) JP3521914B2 (en)
CA (1) CA2256485C (en)
WO (1) WO1997046048A1 (en)

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Also Published As

Publication number Publication date
CA2256485C (en) 2004-02-17
WO1997046048A1 (en) 1997-12-04
US5715319A (en) 1998-02-03
EP0903056A1 (en) 1999-03-24
JP3521914B2 (en) 2004-04-26
JP2001502126A (en) 2001-02-13
EP0903056A4 (en) 2000-01-05

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