公开(公告)号：WO2008090342A3

公开(公告)日：2008-10-30

申请号：PCT/GB2008000237

申请日：2008-01-23

Applicant: WOLFSON MICROELECTRONICS PLC ,  SIBBALD ALASTAIR ,  HOWLE MARTIN

Inventor： SIBBALD ALASTAIR ,  HOWLE MARTIN

IPC: H04R3/00 ,  G10K11/178

CPC classification number: H04R3/00 ,  G10K11/178 ,  G10K2210/1081 ,  H04R1/1083

Abstract: The invention provides improved ambient noise reduction for ear-worn devices, such as earphones and headphones and for other devices worn upon or used in close proximity to the ear, such as cellular telephone handsets, and it provides, in particular, improvements to "feed-forward" ambient noise-reduction systems. Most feed-forward noise-reduction systems available hitherto purport to operate only below about 1 kHz and, even then, provide only relatively modest amounts of noise reduction. In accordance with this invention, predetermined filter parameters, such as the gain and cut-off frequency of a selected filter stage used in the noise-reduction processing, are mathematically modelled and the model is adjusted in real-time, in response to user-interpretation of a graphical display of a predicted residual noise amplitude spectrum. This allows the user to inspect the predicted residual noise level amplitude spectrum and to iteratively adjust the filter parameters to minimise residual noise in a chosen environment. Instead of being made manually by a user, the iterative adjustments may be automated and implemented under computer control, using known data-fitting methods and/or neural networks.

Abstract translation: 本发明为诸如耳机和头戴式耳机之类的耳戴式设备以及佩戴在耳朵上或靠近耳朵使用的其他设备（诸如蜂窝式电话手持设备）提供了改善的环境噪声降低，并且特别地提供了对“馈送 前向“环境降噪系统。 迄今为止，大多数可用的前馈降噪系统只能在约1kHz以下工作，即使这样，也只能提供相对适中的降噪量。 根据本发明，响应于用户定义的参数，在数学上建模预定的滤波器参数（例如在降噪处理中使用的选定滤波器级的增益和截止频率）并且实时调节模型， 解释预测的残余噪声振幅谱的图形显示。 这允许用户检查预测的残余噪声电平幅度谱并且迭代地调整滤波器参数以最小化所选环境中的残余噪声。 使用已知的数据拟合方法和/或神经网络，代替由用户手动进行，迭代调整可以被自动化并且在计算机控制下实现。

公开(公告)号：WO2008139155A8

公开(公告)日：2009-02-19

申请号：PCT/GB2008001601

申请日：2008-05-08

Applicant: WOLFSON MICROELECTRONICS PLC ,  SIBBALD ALASTAIR

Inventor： SIBBALD ALASTAIR

IPC: G10K11/178 ,  H04R3/00

CPC classification number: G10K11/16 ,  G10K11/178 ,  G10K2210/1081 ,  H04M1/6066 ,  H04M1/7253 ,  H04R1/1041 ,  H04R1/1083 ,  H04R5/033 ,  H04R2420/05 ,  H04R2499/11

Abstract: Noise reduction circuitry for a communication apparatus can apply different noise reduction transfer functions, depending on whether a listening device is connected to the apparatus. If no listening device is connected, the noise reduction transfer function can be adapted for use with microphones (12) and speakers (28) that form an integral part of the communication apparatus, which may be a cellular telephone. If a listening device is connected, the noise reduction transfer function can be adapted for use with microphones (12) and speakers (28) that form a part of the listening device. This allows the noise reduction circuitry to provide improved noise reduction performance.

Abstract translation: 用于通信设备的降噪电路可以根据听音设备是否连接到该设备来应用不同的降噪传递功能。 如果没有连接听音装置，则降噪传递功能可适用于形成通信装置的组成部分的麦克风（12）和扬声器（28），扬声器可以是蜂窝电话。 如果连接了听音装置，则降噪传递功能可适用于构成听音装置一部分的麦克风（12）和扬声器（28）。 这允许降噪电路提供改进的降噪性能。

公开(公告)号：WO2008096125A3

公开(公告)日：2009-01-15

申请号：PCT/GB2008000403

申请日：2008-02-06

Applicant: WOLFSON MICROELECTRONICS PLC ,  CLEMOW RICHARD ,  SIBBALD ALASTAIR ,  ALCOCK ROBERT DAVID

Inventor： CLEMOW RICHARD ,  SIBBALD ALASTAIR ,  ALCOCK ROBERT DAVID

IPC: G10K11/178

CPC classification number: H04R1/1083 ,  G10K11/17833 ,  G10K11/17881 ,  G10K11/17885 ,  G10K2210/1081 ,  G10K2210/3028 ,  G10K2210/3039 ,  G10K2210/503 ,  H04R5/033

Abstract: An adaptive, feed-forward, ambient noise-reduction system includes a reference microphone for generating first electrical signals representing incoming ambient noise, and a connection path including a circuit for inverting these signals and applying them to a loudspeaker directed into the ear of a user. The system also includes an error microphone for generating second electrical signals representative of sound (including that generated by the loudspeaker in response to the inverted first electrical signals) approaching the user's ear. An adaptive electronic filter is provided in the connection path, together with a controller for automatically adjusting one or more characteristics of the filter in response to the first and second electrical signals. The system is configured to constrain the operation of the adaptive filter such that it always conforms to one of a predetermined family of filter responses, thereby restricting the filter to operation within a predetermined and limited set of amplitude and phase characteristics.

Abstract translation: 自适应前馈环境降噪系统包括用于产生表示进入的环境噪声的第一电信号的参考麦克风，以及包括用于反转这些信号的电路的连接路径，并将其应用到定向到用户耳朵的扬声器 。 该系统还包括误差麦克风，用于产生代表用户耳朵的代表声音（包括由扬声器产生的响应于倒置的第一电信号）的第二电信号。 连接路径中提供自适应电子滤波器以及响应于第一和第二电信号自动调整滤波器的一个或多个特性的控制器。 该系统被配置为约束自适应滤波器的操作，使得它总是符合预定的滤波器响应族中的一个，从而将滤波器限制在预定和有限的幅度和相位特性集合内的操作。

公开(公告)号：GB2455824A

公开(公告)日：2009-06-24

申请号：GB0810997

申请日：2008-06-16

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： SIBBALD ALASTAIR ,  ALCOCK ROBERT DAVID

IPC: G10K11/178

Abstract: The system comprises an input for receiving an input signal representing ambient noise; a detector 54 for detecting a magnitude of said input signal; and a voice activity detector 58 for determining voiceless periods when said input signal does not contain a signal representing a voice. The detector is adapted to detect the magnitude of said input signal during said voiceless periods, and the system is adapted to operate in a first mode when said input signal is above a threshold value, and a second mode when said input signal is below the threshold value. The first mode comprises generating a noise cancellation signal with a first magnitude for at least partially cancelling the ambient noise. The second mode comprises an "off" mode or a mode for generating a noise cancellation signal with a second magnitude that is less than the first magnitude. The mode change conserves battery power.

公开(公告)号：GB2446982B

公开(公告)日：2009-04-29

申请号：GB0809515

申请日：2007-02-16

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： SIBBALD ALASTAIR ,  HOWLE MARTIN

IPC: H04R1/10 ,  H04R5/033

公开(公告)号：GB2445388B

公开(公告)日：2009-01-07

申请号：GB0702998

申请日：2007-02-16

Applicant: SONAPTIC LTD ,  WOLFSON MICROELECTRONICS PLC

Inventor： SIBBALD ALASTAIR ,  HOWLE MARTIN

IPC: H04R1/10 ,  G10K11/178

公开(公告)号：GB2479674B

公开(公告)日：2011-11-30

申请号：GB201112200

申请日：2006-04-01

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： SIBBALD ALASTAIR

IPC: G10K11/178 ,  H04R1/10

Abstract: The invention provides a noise reduction control system for an ear-worn speaker-carrying device ("ESD"). The system is configured to sense ambient noise and to develop electrical signals which can be used to reduce the amount of said ambient noise audible to a wearer of the ESD. The system sets a plurality of predetermined and discrete noise reduction levels and automatically responds to at least one controlling event, outside the control of the wearer, to set the degree of noise reduction to one of those discrete levels. Typically, the system inverts and filters the electrical signals relating to ambient noise and feeds the inverted and filtered signals to the speaker of the ESD in time for the speaker to generate sounds capable of interfering destructively with the ambient noise.

公开(公告)号：GB2455824B

公开(公告)日：2010-06-09

申请号：GB0810997

申请日：2008-06-16

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： SIBBALD ALASTAIR ,  ALCOCK ROBERT DAVID

IPC: G10K11/178

公开(公告)号：GB2465064A

公开(公告)日：2010-05-12

申请号：GB0919236

申请日：2008-06-16

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： AL-NAIMI KHALDOON ,  MAGRATH ANTHONY JAMES ,  SIBBALD ALASTAIR

IPC: G10K11/178

Abstract: A noise cancellation system 24 has an input for a digital signal having a first sample rate. The digital filter 44 is a split filter composed of a fixed filter 80 and an adaptive high-pass filter 82, which are connected in series to the input in order to receive the digital signal. The fixed filter 80 is preferably an IIR filter. Control circuitry 54 generates at least one control signal, based on the input digital signal, wherein the control signal is applied to the adaptive high-pass filter 82 so as to control a cut-off frequency of the filter 82. A decimator 90 is preferably included to generate a signal at a second, lower sample rate and apply it to the control circuitry 54. This arrangement is suitable for both feedforward and feedback type noise cancelling systems.

公开(公告)号：GB2456846A

公开(公告)日：2009-07-29

申请号：GB0814048

申请日：2008-07-31

Applicant: WOLFSON MICROELECTRONICS PLC

Inventor： HOWLE MARTIN ,  SIBBALD ALASTAIR

IPC: H04R29/00 ,  G01H15/00

Abstract: An ear simulator for telephonometry has an inlet port 62 for receiving sounds from a speaker 18 of a communications device such a mobile phone handset 12, and it has an outlet port 38 in an opposite surface. The ear simulator has at least one additional aperture 60 in the same surface 50 as the inlet port 62, representing acoustic leakage around a mobile phone held against a user's ear. This allows the ear simulator to provide measurement results that more accurately represent the frequency dependent phase response of the transfer function from the handset loudspeaker driver to the ear of a user of the handset. The additional apertures 60 are provided in a raised portion (58, fig 6) of the inlet port surface so as to provide a reference location (65, fig 7B) for the mobile phone handset. The inlet port surface 50 that carries the mobile phone handset may be rotated with respect to the remainder of the ear simulator (fig 10A, 10B).