Ultra-directional microphones

Electrical audio signal processing systems and devices – Directive circuits for microphones

Reexamination Certificate

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Details

Other Related Categories

C381S111000

Type

Reexamination Certificate

Status

active

Patent number

07068796

Description

ABSTRACT:
The present invention provides a highly directional audio response that is flat over five octaves or more by the use of multiple colinear arrays followed by signal processing. Each of the colinear arrays has a common center, but a different spacing so that it can be used for a different frequency range. The response of the microphones for each spacing are combined and filtered so that when the filtered responses are added, the combined response is flat over the selected frequency range. To improve the response, the output of the microphones for a given array spacing can also be filtered with windowing functions. To receive the response from other directions a “steering” delay may also be introduced in the microphone signals before they are combined. The invention also extends to two and three dimensional arrays.

REFERENCES:
patent: 4703506 (1987-10-01), Sakamoto et al.
patent: 4741038 (1988-04-01), Elko et al.
patent: 4802227 (1989-01-01), Elko et al.
patent: 4922536 (1990-05-01), Hoque
patent: 5051799 (1991-09-01), Paul et al.
patent: 5058170 (1991-10-01), Kanamori et al.
patent: 5483599 (1996-01-01), Zagorski
patent: 5684882 (1997-11-01), Mahieux et al.
patent: 5737430 (1998-04-01), Widrow
patent: 5848170 (1998-12-01), Mahieux et al.
patent: 5940118 (1999-08-01), Van Schyndel
patent: 6952697 (2005-10-01), Rothschild
patent: 2 097 121 (1981-04-01), None
patent: 2 104 218 (1981-07-01), None
patent: WO 99/27754 (1999-06-01), None
patent: WO 99/53336 (1999-10-01), None
patent: WO 00/52959 (2000-09-01), None
Peacock, Kenneth L., “On the Practical Design of Discrete Velocity Filters for Seismic Data Processing,”IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. ASSP-30, No. 1, Feb. 1982, pp. 52-60.
Gerzon, Michael, “Ultra-Directional Microphones: Applications of Blumlein Difference Technique: Part 1,”Studio Sound, vol. 12, Oct. 1970, pp. 434-437.
Gerzon, Michael, “Ultra-Directional Microphones: Applications of Blumlein Difference Technique: Part 2,”Studio Sound, vol. 12, Nov. 1970, pp. 501-504.
Gerzon, Michael, “Ultra-Directional Microphones: Applications of Blumlein Difference Technique: Part 3,”Studio Sound, vol. 12, Dec. 1970, pp. 539-543.
Skolnik, Merrill I.,Radar Handbook, 1990.
Harry F. Olson “Directional Microphones,”Journal of the Audio Engineering Society, Oct. 1967. [0002].
B.R. Beavers, R. Brown “Third-Order Gradient Microphone for Speech Reception”Journal of the Audio Engineering Society, Dec. 1970. [0002] NOTE: These two articles, 1) and 2), are included in Microphones: An Anthology of Articles on Microphones from the Pages of the Journal of the Audio.
Section 9.1, pp. 128-134, of Leland B. Jackson “Digital Filters and Signal Processing,”Kluwer Academic Publishers, Hingham, MA USA, 1996. [0029].
Sections 2.5 and 8.6 of Gene H. Golub, Charles F. Van Loan “Matrix Computations: Third Edition”Johns Hopkins University Press, Baltimore MD USA, 1996. [0037].
J.H. McClellan, T.W. Parks, L.R. Rabiner “A Computer Program for Designing Optimum FIR Linear Phase Digital Filters”IEEE Transactions on Audio and Electroacoustics, vol. AU-21, pp. 506-526, Dec. 1973. [0039].
Andrew G. Deczky “Synthesis of Recursive Digital Filters Using the Minimum p-Error Criterion”IEEE Transactions on Audio and Electroacoustics, vol. AU-20, pp. 257-263, Oct. 1972. [0039].
Metcalfe, R.M., and Boggs, D.R. “Ethernet: Distributed Packet Switching for Local Computer Networks”,Communications of the ACM, vol. 19, No. 7, pp. 395-404, Jul. 1976. [0072].
Patrick M. Peterson “Adaptive Array Processing for Multiple Microphone Hearing Aids”RLE Technical Report No. 541, Feb. 1989. (This is from: RLE (Research Laboratory of Electronics), MIT, Cambridge, MA 02139.
Chou, Thomas, “Frequency-Independent Beamformer With Low Response Error,”IEEE Conference on Acoustics, Speech, and Signal Processing, vol. 5, pp. 2995-2998, 1995.
Berhout et al., “Acoustic Control By Wave-Field Synthesis,”Journal of the Acoustic Society of America, vol. 5, pp. 2764-2778, 1993.
Goodwin Michael M.; Elko, Gary W., “Constant Beamwidth Beamforming,”IEE Conference on Acoustics, Speech, and Signal Processing, vol. 4, pp. I-169-I-172, 1993.
Flanagan, J.H. et al. “Autodirective Micro Systems,”Acustica, vol. 73, pp. 58-71, 1991.

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