Electronic noise attenuation system
    1.
    发明授权
    Electronic noise attenuation system 失效
    电子噪声衰减系统

    公开(公告)号:US4783817A

    公开(公告)日:1988-11-08

    申请号:US002242

    申请日:1987-01-12

    摘要: An electronic noise attenuation system for attenuation of non-steady noise occurring in a propagation passage such a duct line by conducting adaptive controls by use of a computer system including a digital filter therein. Sensing microphones M.sub.1, M.sub.2 are located in the propagation passage with a cancellation sound source S therebetween at positions where the transfer functions Hr, Ht of a sound wave generated from the cancellation sound source are equivalent to each other. The output signal of the sensing microphone M.sub.1 and the phase-inverted version of the output signal of the sensing microphone M.sub.2 are input via an add circuit to the control part of the system. The system can prevent the occurrence of an acoustic feedback from the cancellation sound source to the sensing microphone M.sub.1 so as to realize a stable and highly accurate noise attenuation.

    摘要翻译: 一种电子噪声衰减系统,用于通过使用包括数字滤波器的计算机系统进行自适应控制来衰减在诸如管道线路的传播通道中发生的非稳定噪声。 感测麦克风M1,M2位于传播路径中,其中取消声源S在从取消声源产生的声波的传递函数Hr,Ht彼此相等的位置处。 感测麦克风M1的输出信号和感测麦克风M2的输出信号的相位反转版本经由加法电路输入到系统的控制部分。 该系统可以防止从消除声源到感测麦克风M1的声反馈的发生,以实现稳定和高精度的噪声衰减。

    Electronic noise attenuation method and apparatus for use in effecting
such method
    2.
    发明授权
    Electronic noise attenuation method and apparatus for use in effecting such method 失效
    用于实现这种方法的电子噪声衰减方法和装置

    公开(公告)号:US5295192A

    公开(公告)日:1994-03-15

    申请号:US957068

    申请日:1992-10-06

    摘要: A method for electrically attenuating a noise in an area for a sound wave to be propagatable in a three dimensional direction by making up a drive signal from the information on the noise and previously given filter coefficients by use of an adaptive digital filter and then generating an additional sound wave in accordance with the drive signal for cancellation of the noise. In the electric noise attenuation method, there are provided in a given region for noise attenuation, first and second error sensor groups for detecting an interference sound wave produced between the noise and additional sound wave, at a sampling time, a filter coefficient is calculated based on the information relating to the first error sensor group, at the next sampling time, another filter coefficient is calculated based on the information relating to the second error sensor group, and these operations are repeatedly executed sequentially for each error sensor to thereby update the filter coefficient of the adaptive digital filter.

    摘要翻译: 一种用于通过使用自适应数字滤波器通过从关于噪声的信息和先前给定的滤波器系数组成驱动信号来电声衰减在三维方向上可传播的声波区域中的噪声的方法, 附加声波根据驱动信号消除噪声。 在电噪声衰减方法中,在给定的噪声衰减区域中设置用于检测在噪声和附加声波之间产生的干扰声波的第一和第二误差传感器组,在采样时间基础上计算滤波器系数 关于与第一误差传感器组有关的信息,在下一个采样时间,基于与第二误差传感器组相关的信息计算另一个滤波器系数,并且对于每个误差传感器重复执行这些操作,从而更新滤波器 自适应数字滤波器的系数。

    Electronic noise attenuation system
    3.
    发明授权
    Electronic noise attenuation system 失效
    电子噪声衰减系统

    公开(公告)号:US5018202A

    公开(公告)日:1991-05-21

    申请号:US313475

    申请日:1989-02-22

    IPC分类号: H04R3/00 G10K11/178

    摘要: An electronic noise attenuation system for attenuating a sound wave propagated from a source of noise by generating another sound wave 180.degree. out of phase and having the same sound pressure with the propagated sound wave from electro-mechanic transducer means disposed in a propagation passage of sound waves. In the electronic noise attenuation system, a drive signal for drive the electro-mechanic transducer means is generated in accordance with output signals respectively output from upstream-side and downstream-side mechano-electric transducer means respectively disposed in the propagation passage with the electro-mechanic transducer means therebetween. Namely, the drive signal is created by performing an operation on a difference signal between the output signal of the upstream mechano-electric transducer means and the drive signal according to a given transfer function. Also, the transfer function is determined in accordance with the difference signal and the output signal of the downstream mechano-electric transducer means.

    摘要翻译: 一种电子噪声衰减系统,用于衰减从噪声源传播的声波,通过产生与声波传播通道中设置的来自机电传感器装置的传播声波相同并且具有相同声压180°的另一声波 波浪。 在电子噪声衰减系统中,根据从分别设置在传播路径中的上游侧和下游侧机械电传感器装置输出的输出信号,产生用于驱动机电换能器装置的驱动信号, 机械传感器装置在其间。 即,通过根据给定的传递函数对上游机电换能器装置的输出信号和驱动信号之间的差分信号执行操作来创建驱动信号。 而且,传递函数根据差分信号和下游机电换能器装置的输出信号来确定。

    Earphone characteristic measuring device
    4.
    发明授权
    Earphone characteristic measuring device 失效
    耳机特性测量装置

    公开(公告)号:US4586194A

    公开(公告)日:1986-04-29

    申请号:US576476

    申请日:1984-02-02

    IPC分类号: H04R25/04 H04R25/00 H04R29/00

    CPC分类号: H04R29/001 H04R25/30

    摘要: An earphone characteristic measuring device comprises an acoustic coupler having an acoustic tube simulated to an external auditory canal in which an earphone under measurement is to be inserted and an acoustic tube of a smaller diameter having an acoustic impedance of approximately 320 ohms connected to an end of the first acoustic tube, a sound source for emitting an impulse sound to the acoustic coupler, a microphone mounted at the end of the first acoustic tube for picking up sound pressure information and a characteristic calculation circuit for transforming an earphone characteristic of the acoustic coupler to an earphone characteristic of a real ear based on an input impedance of the acoustic coupler viewed from an end of the earphone inserted in the acoustic coupler and an input impedance of the real ear represented by a sum of an eardrum impedance of the real ear and an external auditory canal volume of the real ear, stored in a memory in response to the sound pressure information from the microphone. The use of the acoustic coupler of a simple structure facilitates the measurement of a vent characteristic of the earphone and an insertion gain and improves reliability of the measurement.

    摘要翻译: 耳机特性测量装置包括声耦合器,该声耦合器具有模拟到外耳道的声管,其中待插入的耳机将被插入,声管阻抗约为320欧姆的较小直径的声管连接到 第一声​​管,用于向声耦合器发射脉冲声音的声源,安装在第一声管的端部处用于拾取声压信息的麦克风和用于将声耦合器的耳机特性变换的特性计算电路转换为 基于从插入在声耦合器中的耳机的端部观察的基于声耦合器的输入阻抗的真实耳朵的耳机特性和由真耳朵的鼓膜阻抗之和表示的真耳朵的输入阻抗 外耳道体积的耳朵,存储在记忆中,以响应声压信息 从麦克风。 使用简单结构的声耦合器便于测量耳机的通风特性和插入增益,并提高了测量的可靠性。