公开(公告)号：EP0660958A1

公开(公告)日：1995-07-05

申请号：EP92920842.0

申请日：1992-09-21

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： EATWELL, Graham

IPC: G06J1 ,  H03H17

CPC classification number: H03H17/0283

Abstract: A filter system with low throughput delay having at least two parallel filters, either sampled-data or continuous, wherein one of the filters has a low throughput delay in comparison with the other filters.

公开(公告)号：EP0645004A1

公开(公告)日：1995-03-29

申请号：EP92913860.0

申请日：1992-06-10

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： GOSSMAN, William

IPC: G10K11

Abstract: A system and method for using active algorithmically controlled sensing (1a, 1b) means and speaker means (2a, 2b) for controlling noise from a distributed noise source (5) within an enclosure (6) with a multiple input, multiple output controller (7).

公开(公告)号：EP0643882A1

公开(公告)日：1995-03-22

申请号：EP92913918.0

申请日：1992-06-05

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： EVANS, Robert ,  CLAYBAUGH, David ,  EATWELL, Graham ,  PARRELLA, Michael

IPC: A61F11 ,  H04R5

CPC classification number: H04R1/1083 ,  A61F2011/145 ,  H04R5/033

Abstract: A passive selective headset (11) characterized in that a controller accepts speech noise and warning signals from microphones (14) and allows the user to employ an 'in-wire' controller (17) or an adaptive speech filter (16) to attenuate the noise from the signal fed to the speakers (12) adjacent the user's ear.

公开(公告)号：EP0615648A1

公开(公告)日：1994-09-21

申请号：EP92905531.0

申请日：1991-12-02

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： MC LOUGHLIN, Michael, P. ,  EGHTESADI, Khoscrow ,  SMITH, Dexter ,  ZIEGLER, Eldon, W., Jr.

IPC: G10K11

CPC classification number: G10K11/178 ,  G10K2210/1054 ,  G10K2210/106 ,  G10K2210/3216

Abstract: An active noise (''NOISE SOURCE'') control system for an enclosure having at least two transducers (''SECOND SOURCES'') and multiple channels in which there is interaction between the channels provides for attenuation of the desired regions within the enclosure.

公开(公告)号：EP0594626A1

公开(公告)日：1994-05-04

申请号：EP92902773.0

申请日：1991-07-16

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： ZIEGLER, Eldon, W. ,  McLOUGHLIN, Micahel, P. ,  VERSCHUEREN, Luc ,  EGHTESADI, Khosrow ,  ARNOLD, Michael ,  FRIESEN, Robert

IPC: F04D29 ,  G10K11

CPC classification number: F04D29/663 ,  G10K11/178 ,  G10K2210/101 ,  G10K2210/112 ,  G10K2210/121 ,  G10K2210/3045 ,  G10K2210/509

Abstract: This invention relates to a new type of compact high efficiency fan utilizing microphones (74, 75), a loudspeaker (69, 70) and a totally adaptive noise cancellation controller (73) whereby the design of the fan eliminates broadband noise and the controller reduces the remaining tonal component thus producing a high efficient silent fan.

公开(公告)号：EP0555266A1

公开(公告)日：1993-08-18

申请号：EP91918376.0

申请日：1991-10-22

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： ROSS, Colin Fraser ,  EATWELL, Graham Paul

IPC: G10K11

CPC classification number: G10K11/178 ,  G10K2210/1282 ,  G10K2210/30232 ,  G10K2210/3045 ,  G10K2210/3046 ,  G10K2210/3055 ,  G10K2210/3212 ,  G10K2210/3216

Abstract: An active vibration control system in which an input sensor (2) generates first signals representative of a primary vibration field, actuators (1) are driven by second signals to produce a secondary vibration field, monitoring sensors (3) producing third signals are positioned in a first region (4) differing from a second region where vibration is to be controlled, a controller (5) is responsive to the first signals to generate second signals which reduce vibration in the second region, and the controller is adaptive with reference to the first and third signals to maintain reduced vibration in the second region.

公开(公告)号：EP0516695A1

公开(公告)日：1992-12-09

申请号：EP91904859.0

申请日：1991-02-20

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： ROSS, Colin Fraser ,  LANGLEY, Andrew John ,  EATWELL, Graham Paul

IPC: G10K11

CPC classification number: G10K11/178 ,  G10K2210/108 ,  G10K2210/1081 ,  G10K2210/121 ,  G10K2210/3011 ,  G10K2210/3018 ,  G10K2210/511

Abstract: An active control system for attenuating tonal noise in a defined region is described. In its most basic form the system includes sensors (1, 8) for generating signals indicative of the residual noise in the region after attenuation and the uncontrolled sound affecting the region, signal processing circuits (10, 26) for processing the generated signals differently depending on the tonal content thereof, an adaptive filter (5) supplied with at least one of the generated signals whose characteristic is controlled by the processing circuitry (10), a transducer (6) for producing tonal-noise-attenuating disturbance in the region and delay means (4) for delaying signals relating to the uncontrolled noise before or after or during the adaptive filtering. The system finds direct application in a personal headset or ear defender.

公开(公告)号：EP0659288B1

公开(公告)日：2001-05-30

申请号：EP92915843.4

申请日：1992-07-14

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： ZIEGLER, Eldon ,  SMITH, Dexter ,  MCLOUGHLIN, Michael

IPC: G05B13/02 ,  H03B29/00

CPC classification number: H03G3/32 ,  G05B13/024 ,  G10K11/178 ,  G10K2210/10 ,  G10K2210/112 ,  G10K2210/121 ,  G10K2210/3045 ,  G10K2210/506

Abstract: A simple, low cost active noise cancellation system employing a delay and actuator estimator (35), a gain determination (34), a gain (33) and speaker (36) that cancels stationary random noise such as that encountered on a rangehood fan.

公开(公告)号：EP0705472B1

公开(公告)日：2000-05-10

申请号：EP94922444.8

申请日：1994-06-23

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： JONES, Owen

IPC: G10K11/16

CPC classification number: G10K11/17857 ,  A61F2011/145 ,  G10K11/17855 ,  G10K11/17881 ,  G10K11/17885 ,  G10K2210/108 ,  G10K2210/1081 ,  G10K2210/3011 ,  G10K2210/3013 ,  G10K2210/3019 ,  G10K2210/3028 ,  G10K2210/3056 ,  G10K2210/3214 ,  G10K2210/503

Abstract: An active noise cancellation system includes a series of features for more effective cancellation, greater reliability, and improved stability. A particular feature adapted for headset systems includes locating a residual microphone radially offset from the centre of a sound generator to detect a signal more similar to that incident upon the eardrum of the user. In addition, an open back headset design includes perforations on the side of the headset instead of the back, so that the perforations are less susceptible to inadvertent blockage. The system also includes a mechanism for detecting changes in the acoustic characteristics of the environment that may be caused, for example, by pressure exerted upon the earpieces, and that may destabilize the cancellation system. The system automatically responds to such changes, for example, by reducing the gain or the frequency response of the system to preserve stability. The system further includes other methods for detecting imminent instability and compensating, such as detecting the onset of signals within enhancement frequencies characteristic of the onset of instability, and adjusting the gain of frequency response of the system or suppressing the enhanced signals. The system further includes a mechanism for conserving battery life by turning the system off when sound levels are low, or adjusting the power supply to the system to correspond to the current power requirements of the system.

公开(公告)号：EP0555266B1

公开(公告)日：1998-09-02

申请号：EP91918376.4

申请日：1991-10-22

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： ROSS, Colin Fraser ,  EATWELL, Graham Paul

IPC: G10K11/16

CPC classification number: G10K11/178 ,  G10K2210/1282 ,  G10K2210/30232 ,  G10K2210/3045 ,  G10K2210/3046 ,  G10K2210/3055 ,  G10K2210/3212 ,  G10K2210/3216

Abstract: An active vibration control system in which an input sensor (2) generates first signals representative of a primary vibration field, actuators (1) are driven by second signals to produce a secondary vibration field, monitoring sensors (3) producing third signals are positioned in a first region (4) differing from a second region where vibration is to be controlled, a controller (5) is responsive to the first signals to generate second signals which reduce vibration in the second region, and the controller is adaptive with reference to the first and third signals to maintain reduced vibration in the second region.