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    Digital circuit arrangements for ambient noise-reduction
    1.
    发明公开
    Digital circuit arrangements for ambient noise-reduction 审中-公开
    数字电路安排环境降噪

    公开(公告)号：EP2469888A3

    公开(公告)日：2017-06-07

    申请号：EP12158950.1

    申请日：2007-04-11

    申请人： Cirrus Logic International Semiconductor Limited

    发明人： Clemow, Richard

    IPC分类号： H04R3/02 ,  G10K11/178 ,  H04R1/10

    CPC分类号： G10K11/178 ,  G10K11/16 ,  G10K2210/1081 ,  G10K2210/3051 ,  G10K2210/3217 ,  H04R1/1083 ,  H04R3/02

    摘要： The invention provides a digital circuit arrangement for an ambient noise-reduction system affording a higher degree of noise reduction than has hitherto been possible, through the use of a low latency signal processing chain consisting of analogue-to-digital conversion, digital processing and digital-to-analogue conversion. The arrangement converts the analogue signals into N-bit digital signals at sample rate f o , 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 f o 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.

    摘要翻译： 本发明提供了一种用于环境噪声降低系统的数字电路装置，通过使用由模数转换，数字处理和数字信号组成的低等待时间信号处理链，提供比迄今可能的更高程度的噪声降低 模拟转换。 该配置将模拟信号转换成采样率为f的N位数字信号，然后对转换后的信号进行数字滤波。 在一些实施例中，N的值是1，但是无论如何不大于8，并且fo可以是奈奎斯特采样率的64倍，但是在任何情况下都大大高于奈奎斯特采样率。 这允许使用数字处理，而不会产生排除在此情况下使用常规数字处理的群延迟问题。 此外，可以很容易地实现群延迟的调整，以微秒为单位，为前馈应用提供微调群延时的能力。

    Low frequency active noise control
    2.
    发明公开
    Low frequency active noise control 有权
    低频有源噪声衰减

    公开(公告)号：EP1249829A3

    公开(公告)日：2006-09-13

    申请号：EP02076358.7

    申请日：2002-04-05

    申请人： Siemens VDO Automotive Inc.

    发明人： McWilliam, Richard Donald

    IPC分类号： G10K11/178

    CPC分类号： G10K11/178 ,  G10K2210/112 ,  G10K2210/1282 ,  G10K2210/3026 ,  G10K2210/3214 ,  G10K2210/3217

    摘要： A noise attenuation system (10) for an air induction system (12) includes an air inlet duct (16) having an open end (18) to draw in air and a loudspeaker (22) mounted within the inlet duct (16) and facing the open end (18) of the inlet duct (16). The air horn (24) is connected to the loudspeaker (22) to tune the sound output and increase the sound power from the loudspeaker (22) to optimize cancellation of noise generated by the air induction system (16) at lower frequencies. An open end (18) of the air horn (24) is positioned within a plane defined by the open end (18) of the air inlet duct (16). A microphone (26) is positioned near the air inlet duct (16) and is in communication with a controller (28). The controller (28) generates an input to the loudspeaker (22). The input to the loudspeaker (22) is out of phase with the noise detected by the microphones (26) to cancel a portion of noise emitted from the open end (18) of the air inlet (16).

    DISPOSITIF ACTIF D'ATTENUATION DE L'INTENSITE SONORE
    8.
    发明公开
    DISPOSITIF ACTIF D'ATTENUATION DE L'INTENSITE SONORE 失效
    有源器件声音烈度衰减

    公开(公告)号：EP0787340A1

    公开(公告)日：1997-08-06

    申请号：EP95934193.0

    申请日：1995-10-10

    申请人： LE COMPTOIR DE LA TECHNOLOGIE

    发明人： GAUDRIOT, Lionel ,  MARTINAT, Jacques

    IPC分类号： G10K11

    CPC分类号： G10K11/178 ,  G10K2210/10 ,  G10K2210/103 ,  G10K2210/12 ,  G10K2210/124 ,  G10K2210/3046 ,  G10K2210/3217 ,  G10K2210/512

    摘要： Active device for attenuating the sound intensity in a predetermined area by emitting counternoise waves, of the type comprising an assembly of sensors (7a, 7b, 7c) capable of determining the signals and directions of waves (20) emitted by the remote noise sources; means for processing the signals b(t) issued from said sensors, and for generating the signals cb(t) corresponding to the coounternoise waves; an assembly of electroacoustic sources (2) connected to said means, and capable of emitting counternoise waves in the same direction and orientation as incident waves, the sensors and electroacoustic sources being placed in such a way that the incident waves reach previously the sensors, the disclosed device being characterized in that the electroacoustic sources (2) are installed in a space close to the area to be protected and in that the counternoise waves (22) emitted by the assembly of electroacoustic sources (2) combine in order to form waves which admit the incident waves (20) as envelopes.