公开(公告)号：US09558729B2

公开(公告)日：2017-01-31

申请号：US14142329

申请日：2013-12-27

Applicant: Wolfson Microelectronics plc

Inventor： Richard Clemow

IPC: G10K11/16 ,  H04R3/02 ,  H04R1/10 ,  G10K11/178

CPC classification number: G10K11/178 ,  G10K11/16 ,  G10K2210/1081 ,  G10K2210/3051 ,  G10K2210/3217 ,  H04R1/1083 ,  H04R3/02

Abstract: A digital circuit arrangement for an ambient noise-reduction system affording a higher degree of noise reduction than has hitherto been possible. The arrangement converts the analog signals into N-bit digital signals at sample rate f0, and then subjects the converted signals to digital filtering. The value of N in some embodiments is 1 but, in any event, is no greater than 8, and f0 may be 64 times the Nyquist sampling rate but, in any event, is substantially greater than the Nyquist sampling rate. This permits digital processing to be used without incurring group delay problems that rule out the use of conventional digital processing in this context. Furthermore, adjustment of the group delay can readily be achieved, in units of a fraction of a micro-second, providing the ability to fine tune the group delay for feed forward applications.

Abstract translation: 用于环境降噪系统的数字电路装置提供比迄今为止可能更高程度的噪声降低的数字电路装置。 该装置将模拟信号以采样率f0转换为N位数字信号，然后将转换的信号转换为数字滤波。 在一些实施例中，N的值为1但是在任何情况下都不大于8，并且f0可以是奈奎斯特采样率的64倍，但是在任何情况下都大大地高于奈奎斯特采样率。 这允许使用数字处理，而不会导致在这种情况下排除使用常规数字处理的组延迟问题。 此外，可以容易地实现组延迟的调整，以微秒的一小部分为单位，提供微调前馈应用的组延迟的能力。

公开(公告)号：US20140105413A1

公开(公告)日：2014-04-17

申请号：US14054555

申请日：2013-10-15

Applicant: Wolfson Microelectronics plc

Inventor： Richard Clemow

IPC: G10K11/175

CPC classification number: G10K11/002 ,  G10K11/175 ,  G10K11/178 ,  G10K2210/3027 ,  G10K2210/3028 ,  H03G3/002 ,  H04R1/1008

Abstract: A noise cancellation signal is generated by generating an ambient noise signal, representing ambient noise, and generating a noise cancellation signal, by applying the ambient noise signal to an feedforward filter, where the feedforward filter comprises a high-pass filter having an adjustable cut-off frequency, and by applying a controllable gain. The noise cancellation signal is then applied to a loudspeaker, to generate a sound to at least partially cancel the ambient noise. An error signal is generated, representing unwanted sound in the region of the loudspeaker. The phase of the ambient noise signal is compared to a phase of the error signal, and the gain is controlled on the basis of a result of the comparison, taking account of a phase shift introduced by the high-pass filter when performing the comparison.

Abstract translation: 噪声消除信号是通过将环境噪声信号施加到前馈滤波器来产生表示环境噪声的环境噪声信号，以及产生噪声消除信号，其中前馈滤波器包括具有可调节切断信号的高通滤波器， 关闭频率，并通过应用可控增益。 然后将噪声消除信号施加到扬声器，以产生声音以至少部分地消除环境噪声。 产生一个错误信号，表示扬声器区域内的不必要的声音。 将环境噪声信号的相位与误差信号的相位进行比较，并且在进行比较时考虑到高通滤波器引入的相移，基于比较结果来控制增益。

公开(公告)号：US20140112492A1

公开(公告)日：2014-04-24

申请号：US14142329

申请日：2013-12-27

Applicant: Wolfson Microelectronics plc

Inventor： Richard Clemow

IPC: G10K11/16

CPC classification number: G10K11/178 ,  G10K11/16 ,  G10K2210/1081 ,  G10K2210/3051 ,  G10K2210/3217 ,  H04R1/1083 ,  H04R3/02

Abstract: A digital circuit arrangement for an ambient noise-reduction system affording a higher degree of noise reduction than has hitherto been possible. The arrangement converts the analog signals into N-bit digital signals at sample rate f0, and then subjects the converted signals to digital filtering. The value of N in some embodiments is 1 but, in any event, is no greater than 8, and f0 may be 64 times the Nyquist sampling rate but, in any event, is substantially greater than the Nyquist sampling rate. This permits digital processing to be used without incurring group delay problems that rule out the use of conventional digital processing in this context. Furthermore, adjustment of the group delay can readily be achieved, in units of a fraction of a micro-second, providing the ability to fine tune the group delay for feed forward applications.

Abstract translation: 用于环境降噪系统的数字电路装置提供比迄今为止可能更高程度的噪声降低的数字电路装置。 该装置将模拟信号以采样率f0转换为N位数字信号，然后将转换的信号转换为数字滤波。 在一些实施例中，N的值为1但是在任何情况下都不大于8，并且f0可以是奈奎斯特采样率的64倍，但是在任何情况下都大大地高于奈奎斯特采样率。 这允许使用数字处理，而不会导致在这种情况下排除使用常规数字处理的组延迟问题。 此外，可以容易地实现组延迟的调整，以微秒的一小部分为单位，提供微调前馈应用的组延迟的能力。