Patent US4893342A successfully refreshed from Google Patents.
US4893342A
Expired / Lapsed
US
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Head diffraction compensated stereo system
Assignee: COOPER BAUCK Corp
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Filing: 1987-10-15
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Granted: 1990-01-09
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Expires: 2007-10-15
Abstract
Abstract A stereo audio processing system for a stereo audio signal processing reproduction that provides improved source imaging and simulation of desired listening environment acoustics while retaining relative independence of listener movement. The system first utilizes a synthetic or artificial head microphone pickup and utilizes the results as inputs to a cross-talk cancellation and naturalization compensation circuit utilizing minimum phase filter circuits to adapt the head diffraction compensated signals for use as loudspeaker signals. The system provides for head diffraction compensation including cross-coupling while permitting listener movement by limiting the cross-talk cancellation and diffraction compensation to frequencies substantially below approximately ten kilohertz.
Inventors
- 👤 Duane H. Cooper
- 👤 Jerald L. Bauck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:29
CPC Classifications
H; H04; H04S; H04S1/00; H04S1/002; H04S1/005
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
112 words
An audio processing system for generating compensated audio signals suitable for reproduction through a loudspeaker system, comprising: source means for providing two channels of audio signals having head-related transfer functions imposed thereon; compensation means for providing cross-talk cancellation of the audio signals and for providing naturalization compensation of the audio signals to correct for propagation path distortion including filtering means for substantially modifying frequency and phase response of the cross-talk cancellation and naturalization compensation at frequencies beginning at a frequency above 600 hertz and beginning at least at a frequency below ten kilohertz in such a way as to release the cross-talk cancellation at such high frequencies thereby generating compensated audio signals.
Claim 2
Dependent Claim
112 words
An audio processing system for generating compensated audio signals suitable for reproduction through a loudspeaker system, comprising: source means for providing two channels of audio signals having head-related transfer functions imposed thereon; compensation means for providing cross-talk cancellation of the audio signals and for providing naturalization compensation of the audio signals to correct for propagation path distortion including filtering means for substantially modifying frequency and phase response of the cross-talk cancellation and naturalization compensation at frequencies beginning at a frequency above 600 hertz and beginning at least at a frequency below ten kilohertz in such a way as to release the cross-talk cancellation at such high frequencies thereby generating compensated audio signals.
Claim 3
Dependent Claim
28 words
The audio processing system of claim 1 wherein the compensation means comprises means for substantially limiting the crosstalk cancellation and naturalization compensation to frequencies substantially below ten kilohertz.
Claim 4
Dependent Claim
28 words
The audio processing system of claim 1 comprising a synthetic head means for generating the two channels of audio signals and simulating the effects of head related diffraction.
Claim 5
Dependent Claim
23 words
The audio processing system of claim 3 wherein the synthetic head means comprises a plurality of signal sources each having a directional assignment.
Claim 6
Dependent Claim
16 words
The audio processing system of claim 4 wherein the synthetic head simulates a typical human head.
Claim 7
Dependent Claim
28 words
The audio processing system of claim 3 wherein the synthetic head means comprises a plurality of directionalized microphones and filter structures to simulate the effects of head diffraction.
Claim 8
Dependent Claim
16 words
The audio processing system of claim 4 wherein the synthetic head simulates spherical head diffraction effects.
Claim 9
Dependent Claim
19 words
The audio processing system of claim 1 wherein the compensation means is a shuffler structure utilizing minimum delay filters.
Claim 10
Dependent Claim
34 words
The audio processing system of claim 8 wherein the compensating means processes the audio signals such that the compensated audio signals are formatted for reproduction through loudspeakers placed at a predetermined speaker bearing angle.
Claim 11
Dependent Claim
40 words
The audio processing system of claim 2 wherein the source means provides stereo audio signals formatted for a predetermined speaker bearing angle and the compensation means comprises means for reformatting the audio signals for a different selected speaker bearing angle.
Claim 12
Dependent Claim
71 words
An audio processing system for processing audio signals to generate compensated audio signals suitable for reproduction through loudspeakers comprising: source means for providing two channels of audio signals and for imposing effects of head related diffraction effects thereon; and processing means for processing the audio signals to cancel the effects of propagation from the loudspeakers to the ears of a listener, said processing substantially limited to frequencies substantially below ten kilohertz.
Claim 13
Dependent Claim
71 words
An audio processing system for processing audio signals to generate compensated audio signals suitable for reproduction through loudspeakers comprising: source means for providing two channels of audio signals and for imposing effects of head related diffraction effects thereon; and processing means for processing the audio signals to cancel the effects of propagation from the loudspeakers to the ears of a listener, said processing substantially limited to frequencies substantially below ten kilohertz.
Claim 14
Dependent Claim
22 words
The audio processing system of claim 11 wherein the source means imposes diffraction effects of a replica of a typical human head.
Claim 15
Dependent Claim
21 words
The audio processing system of claim 11 wherein the processing means comprises filters having characteristics derived from a spherical head model.
Claim 16
Dependent Claim
25 words
The audio processing system of claim 11 wherein the processing means comprises a shuffler network comprising crosstalk cancellation, and minimum delay Sigma and Delta filters.
Claim 17
Dependent Claim
21 words
The audio processing system of claim 14 wherein the Sigma and Delta filter characteristics are derived from a spherical head model.
Claim 18
Dependent Claim
30 words
The audio processing system of claim 11 wherein the source means comprises a synthetic head using a plurality of signal sources and a filter array to simulate head diffraction effects.
Claim 19
Independent Claim
77 words
A method for processing audio signals for reproduction through loudspeakers comprising the step of: generating two channels of audio signals having head-related diffraction effects imposed thereon; and processing the audio signals to provide cross-talk cancellation for the effects of propagation from the loudspeakers to the ears of a listener and modifying the processing at high frequencies beginning at a frequency below ten kilohertz to reduce the cross-talk cancellation at such high frequencies to produce compensated audio signals.
Claim 20
Independent Claim
77 words
A method for processing audio signals for reproduction through loudspeakers comprising the step of: generating two channels of audio signals having head-related diffraction effects imposed thereon; and processing the audio signals to provide cross-talk cancellation for the effects of propagation from the loudspeakers to the ears of a listener and modifying the processing at high frequencies beginning at a frequency below ten kilohertz to reduce the cross-talk cancellation at such high frequencies to produce compensated audio signals.
Claim 21
Dependent Claim
17 words
The method of claim 17 further comprising the step of reproducing the compensated audio signals through loudspeakers.
Claim 22
Dependent Claim
29 words
The method of claim 17 wherein the step of processing comprises the step of compensating based upon an artificial head which is a replica of a typical human head.
Claim 23
Dependent Claim
35 words
The method of claim 17 wherein the step of generating comprises the step of generating each channel of audio signals by simulation of the head related diffraction effects utilizing a signal source and filter array.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-08 | 1993-07-10 | 1994-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-08 | 1997-07-10 | 1998-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-08 | 2001-07-10 | 2002-01-09 | $7700.00 | Window Closed / Lapsed |