Adaptive personal active noise reduction system

• US 6,898,290 B1
• Filed: 03/27/2000
• Issued: 05/24/2005
• Est. Priority Date: 05/06/1997
• Status: Expired due to Fees

• Current Assignee: Aegisound LLC
• Original Assignee: Adaptive Technologies, Inc.
• Inventors: Saunders, William Richard, Vaudrey, Michael Allen
• Primary Examiner(s): Mei, Xu
• Application Number:
  US09/534,731
• Time in Patent Office: 1,884 Days
• Field of Search: 381/71.6, 381/72, 381/74, 381/73.1, 381/370, 381/371, 381/375, 381/378, 381/71.7, 381/384, 381/94.2, 381/94.3
• US Class Current: 381/71.6
• CPC Class Codes: G10K 11/17854 the filter being an adaptive filter
• CPC Class Codes: G10K 11/17857 Geometric disposition, e.g. placement of microphones
• CPC Class Codes: G10K 11/17881 the reference signal being an acoustic signal, e.g. recorded with a microphone
• CPC Class Codes: G10K 2210/10 Applications
• CPC Class Codes: G10K 2210/101 One dimensional
• CPC Class Codes: G10K 2210/108 Communication systems, e.g. where useful sound is kept and noise is cancelled
• CPC Class Codes: G10K 2210/1081 Earphones, e.g. for telephones, ear protectors or headsets
• CPC Class Codes: G10K 2210/1082 Microphones, e.g. systems using "virtual" microphones
• CPC Class Codes: G10K 2210/128 Vehicles
• CPC Class Codes: G10K 2210/1282 Automobiles
• CPC Class Codes: G10K 2210/3016 Control strategies, e.g. energy minimization or intensity measurements
• CPC Class Codes: G10K 2210/3025 Determination of spectrum characteristics, e.g. FFT
• CPC Class Codes: G10K 2210/3026 Feedback
• CPC Class Codes: G10K 2210/3027 Feedforward
• CPC Class Codes: G10K 2210/3031 Hardware, e.g. architecture
• CPC Class Codes: G10K 2210/3033 Information contained in memory, e.g. stored signals or transfer functions
• CPC Class Codes: G10K 2210/30351 Identification of the environment for applying appropriate model characteristics
• CPC Class Codes: G10K 2210/3042 Parallel processing
• CPC Class Codes: G10K 2210/3046 Multiple acoustic inputs, multiple acoustic outputs
• CPC Class Codes: G10K 2210/3056 Variable gain
• CPC Class Codes: G10K 2210/3214 : Architectures, e.g. special constructional features or arrangements of features
• CPC Class Codes: G10K 2210/3217 : Collocated sensor and cancelling actuator, e.g. "virtual earth" designs
• CPC Class Codes: G10K 2210/3219 : Geometry of the configuration
• CPC Class Codes: G10K 2210/3221 : Headrests, seats or the like, for personal ANC systems
• CPC Class Codes: G10K 2210/3222 : Manual tuning
• CPC Class Codes: G10K 2210/506 : Feedback, e.g. howling
• CPC Class Codes: G10K 2210/511 : Narrow band, e.g. implementations for single frequency cancellation
• CPC Class Codes: H04R 1/1083 : Reduction of ambient noise active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06

Abstract

An improved personal noise attenuation system which attenuates both tonal and broadband sound and which includes a spatially adjustable acousto-electric sensor and attenuation means including both feedback and feed forward components so as to provide a heteronomous attenuation and more complete active noise attenuation and the adjustable acousto-electric sensor is moved to exploit the changing physical characteristics of spatial silent zones in different noise fields.

Claims

1. An improved active noise cancellation headset, said headset comprising:

a headgear means for placement atop a user'"'"'s head;

at least one electro-acoustic transducer means mounted on said headgear means;

at least one acoustic-electro sensing means mounted on said headgear means adjacent to said electro-acoustic means, wherein said electro acoustic means and said acoustic-electro means are adjustable in relation to one another and user'"'"'s ears within a designated range, the area containing said electro-acoustic means and said acoustic-electro means defining a zone adjacent to at least one of the user'"'"'s ears;

attenuation control means of heteronomous design connected to said electro acoustic means and to said acoustic-electro means and adapted to attenuate selected sound frequencies in a sound field within said zone; and

whereby said headset is adapted to cancel designated frequencies within said zone to create an area of silence or relative silence to the at least one of a user'"'"'s ears.

2. The headset of claim 1 wherein said attenuation control means includes an automatic mechanism for continually adjusting said electro-acoustic and said acoustic-electro means in relation to one another.

3. The headset as in claim 1 wherein said heteronomous attenuation control means comprises,

a feedforward control means adapted to attenuate designated tonal sounds within said zone, and

a feedback control means adapted to attenuate designated broadband sounds within said zone.

4. The headset of claim 3 wherein said heteronomous attenuation control means further comprises a switch means adapted to permit activation of the feedforward control means without activating the feedback control means, activation of the feedback control means without activating the feedforward control means, and activation of both the feedback control means and the feedforward control means simultaneously.