公开(公告)号：EP0705471B1

公开(公告)日：1999-08-18

申请号：EP94921355.7

申请日：1994-06-22

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： JONES, Owen

IPC: G10K11/16

CPC classification number: G10K11/178 ,  G10K2210/1081 ,  G10K2210/3028 ,  G10K2210/3039 ,  G10K2210/3045

Abstract: The susceptibility of an active noise cancellation system to overloading due to very low frequencies is reduced by subtracting the low frequency components of an applied noise field from the residual signal. Low frequency components of the applied noise field outside the normal range of human hearing are detected by an external sensor and isolated by a filter circuit. The isolated low frequency signal is subtracted from the residual signal, resulting in a modified residual signal with reduced low frequency components. The cancellation system thus eliminates very low frequency cancellation signals, without sacrificing bandwidth or system performance within the audible range.

公开(公告)号：EP0848893A1

公开(公告)日：1998-06-24

申请号：EP96928521.0

申请日：1996-08-21

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： JONES, Owen

IPC: G10K11 ,  H04R1 ,  H04R5

CPC classification number: H04R1/1083 ,  G10K11/178 ,  G10K2210/1081 ,  G10K2210/321 ,  G10K2210/3219 ,  H04R5/033

Abstract: An earpiece for a headset, especially a headset incorporating active unwanted noise suppression, wherein the earshell incorporates a baffle plate carrying a sound drive and an ear cushion, whereby the baffle plate also carries an upstanding projection, more especially in the form of a sound transparent dome, which limits the extent to which the cushion can be compressed when the earpiece is pressed inwardly against the ear from its normally fitted condition.

公开(公告)号：EP0705472A1

公开(公告)日：1996-04-10

申请号：EP94922444.0

申请日：1994-06-23

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： JONES, Owen

IPC: A61F11 ,  G10K11

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：EP0693212B1

公开(公告)日：1999-12-08

申请号：EP94912401.0

申请日：1994-04-07

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： GIFFORD, Carl, S. ,  JONES, Owen ,  TRINDER, Michael, Charles, John

IPC: G10K11/16

CPC classification number: F16F15/002 ,  F16F13/26 ,  F16F15/02 ,  G10K11/178 ,  G10K2210/121 ,  G10K2210/1282 ,  G10K2210/129 ,  G10K2210/1291 ,  G10K2210/3013 ,  G10K2210/30232 ,  G10K2210/3026 ,  G10K2210/3027 ,  G10K2210/3032 ,  G10K2210/3037 ,  G10K2210/3042 ,  G10K2210/3045 ,  G10K2210/3211 ,  G10K2210/3213 ,  G10K2210/501 ,  G10K2210/503 ,  G10K2210/511

Abstract: A vibration control system includes a processor-based circuit which monitors and controls an analog vibration control circuit. The system includes a sensor to detect the undesirable vibrations and a synchronous pulse generator for determining the fundamental frequency of the vibrations emitted by the source. An actuator produces anti-noise to counter unwanted vibrations. The processor circuit tests the system, monitors system functions, and adjusts various parameters to provide optimal performance.

公开(公告)号：EP0542784B1

公开(公告)日：1996-06-05

申请号：EP91913607.7

申请日：1991-07-19

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： JONES, Owen ,  TRINDER, Michael, Charles, John Rymer

IPC: H04R1/42 ,  F16F15/02 ,  F15B7/00

CPC classification number: B60K5/1283 ,  F15B7/005 ,  F16F15/023 ,  F16F15/027 ,  F16F15/03 ,  H04R1/42

Abstract: An actuator having a linear current force characteristic comprises a moving coil transducer and a hydraulic lever. The moving coil (9) is capable of producing only a relatively low force but with a relatively large displacement. The coil (9) is formed on a piston (8) which acts as an input piston to a hydraulic lever. An output piston (13) has a much larger area than the input piston (8). Thus, the long throw, low force input to the hydraulic lever is converted into a short throw, high force output at the second piston (13).

公开(公告)号：EP0693212A1

公开(公告)日：1996-01-24

申请号：EP94912401.0

申请日：1994-04-07

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： GIFFORD, Carl, S. ,  JONES, Owen ,  TRINDER, Michael, Charles, John

IPC: F16F13 ,  F16F15 ,  G10K11

CPC classification number: F16F15/002 ,  F16F13/26 ,  F16F15/02 ,  G10K11/178 ,  G10K2210/121 ,  G10K2210/1282 ,  G10K2210/129 ,  G10K2210/1291 ,  G10K2210/3013 ,  G10K2210/30232 ,  G10K2210/3026 ,  G10K2210/3027 ,  G10K2210/3032 ,  G10K2210/3037 ,  G10K2210/3042 ,  G10K2210/3045 ,  G10K2210/3211 ,  G10K2210/3213 ,  G10K2210/501 ,  G10K2210/503 ,  G10K2210/511

Abstract: A vibration control system includes a processor-based circuit which monitors and controls an analog vibration control circuit. The system includes a sensor to detect the undesirable vibrations and a synchronous pulse generator for determining the fundamental frequency of the vibrations emitted by the source. An actuator produces anti-noise to counter unwanted vibrations. The processor circuit tests the system, monitors system functions, and adjusts various parameters to provide optimal performance.

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：EP0596971B1

公开(公告)日：1997-11-12

申请号：EP92916388.9

申请日：1992-07-28

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： JONES, Owen ,  TRINDER, Michael, Charles, John

IPC: G10K11/16

CPC classification number: G10K11/178 ,  G10K2210/121 ,  G10K2210/3028 ,  G10K2210/3032 ,  G10K2210/3045 ,  G10K2210/3211 ,  G10K2210/3212

Abstract: PCT No. PCT/GB92/01399 Sec. 371 Date May 26, 1994 Sec. 102(e) Date May 26, 1994 PCT Filed Jul. 28, 1992 PCT Pub. No. WO93/03479 PCT Pub. Date Feb. 18, 1993A system for reducing periodic noise, which includes a plurality of harmonically related noise signals, comprises an actuator for producing a canceling acoustic signal, a sensor for detecting a residual noise signal, a synchronizing signal generator and processing circuitry. The processing circuitry comprises a plurality of tunable harmonically related band pass filters, a tuning signal generator and a summer which sums the outputs of the filters. The tuning signal generator receives the synchronizing signal from the synchronizing signal generator and outputs the tuning signals to the band pass filters. As the frequency of the synchronizing signal changes, the tuning signal generator causes the tunable filters to track harmonics of the noise to be canceled. After summing by the summer and suitable amplification, the outputs from the filters are used to drive the actuator so as to reduce the residual noise detected by the sensor.

Abstract translation: 一种用于减少包括多个谐波相关噪声信号的周期性噪声的系统包括用于产生消除声信号的致动器（1），用于检测残余噪声信号的传感器（3），同步信号产生装置（7）和 处理电路（4-1，... 4-n，5，6）。 处理电路包括多个可调和的谐波相关带通滤波器（4-1，... 4-n），调谐信号发生器（6）和加法器（5），其将滤波器（4-1， ，... 4-n）。 调谐信号发生器（6）接收来自同步信号发生装置（7）的同步信号并将调谐信号输出到带通滤波器（4-1，... 4-n）。 当同步信号的频率改变时，调谐信号发生装置（6）使可调谐滤波器（4-1，... 4-n）跟踪要消除的噪声的谐波。 在加法器（5）和适当的放大相加之后，来自滤波器（4-1，... 4-n）的输出被用于驱动致动器（1），以减少由传感器检测到的残余噪声 3）。 在一个实施例中，滤波器（4-1，...，4-n）通过开关电容滤波器来实现。

公开(公告)号：EP0705471A1

公开(公告)日：1996-04-10

申请号：EP94921355.0

申请日：1994-06-22

Applicant: NOISE CANCELLATION TECHNOLOGIES, INC.

Inventor： JONES, Owen

IPC: G10K11

CPC classification number: G10K11/178 ,  G10K2210/1081 ,  G10K2210/3028 ,  G10K2210/3039 ,  G10K2210/3045

Abstract: The susceptibility of an active noise cancellation system to overloading due to very low frequencies is reduced by subtracting the low frequency components of an applied noise field from the residual signal. Low frequency components of the applied noise field outside the normal range of human hearing are detected by an external sensor and isolated by a filter circuit. The isolated low frequency signal is subtracted from the residual signal, resulting in a modified residual signal with reduced low frequency components. The cancellation system thus eliminates very low frequency cancellation signals, without sacrificing bandwidth or system performance within the audible range.

Abstract translation: 通过从残余信号中减去所施加的噪声场的低频分量来减少主动噪声消除系统由于非常低的频率而导致的过载的敏感度。 外部传感器（14）检测在人听力正常范围之外的施加噪声场的低频分量，并由滤波器电路（15）隔离。 从残余信号中减去隔离的低频信号，产生具有减少的低频分量的修改的残余信号。 消除系统因此消除了非常低的频率消除信号，而不牺牲可听范围内的带宽或系统性能。