4.
    发明专利
    未知

    公开(公告)号:DE602004026836D1

    公开(公告)日:2010-06-10

    申请号:DE602004026836

    申请日:2004-02-24

    Abstract: Resonant frequencies f2 and f3 detected in a resonant space are determined as center frequencies of a dip. Based on measurement values at a speaker and a microphone in the resonant space, a basic amplitude frequency characteristic Ca and a target amplitude frequency characteristic Cd are found. A smoothness degree on a frequency axis is larger in the target amplitude frequency characteristic Cd than the basic amplitude frequency characteristic Ca. A damping level and quality factor of the dip are determined based on a difference between the basic amplitude frequency characteristic Ca and the target amplitude frequency characteristic Cd in the center frequencies f2 and f3 of the dip and frequencies near the center frequencies.

    HOWLING MARGIN MEASURING DEVICE
    6.
    发明公开
    HOWLING MARGIN MEASURING DEVICE 有权
    测量装置反馈RESERVE

    公开(公告)号:EP1655993A4

    公开(公告)日:2009-06-10

    申请号:EP04746766

    申请日:2004-06-24

    Applicant: TOA CORP

    CPC classification number: H04R29/007 H04R3/02 H04R27/00 H04R2227/007

    Abstract: A howling margin measuring device (20), comprising a treatment means (28) having a gain regulating means (21) and a compressor (22) connected in series to each other and a control means (23). The gain regulating means (21) gives a gain to an inputted voice signal and outputs that signal, and the compressor (22) compresses the voice signal at a specified ratio when the level of the inputted voice signal is equal to or higher than a threshold level and outputs that signal. The control means (23) can control the gain of the gain regulating means (21), and can read the compression level of the compressor (22). The control means (23) reads the compression level of the compressor (22) while gradually increasing the gain of the gain regulating means (21) and, based on whether the read compression level is above a specified value or not, determines whether howling occurs or not. Then, based on the gain of the gain regulating means (21) obtained when the control means (23) determines that howling occurs, the control means (23) calculates howling margin.

    RESONANCE FREQUENCY DETERMINING METHOD, RESONANCE FREQUENCY SELECTING METHOD, AND RESONANCE FREQUENCY DETERMINING APPARATUS
    9.
    发明公开
    RESONANCE FREQUENCY DETERMINING METHOD, RESONANCE FREQUENCY SELECTING METHOD, AND RESONANCE FREQUENCY DETERMINING APPARATUS 有权
    法确定的共振频率,方法选择谐振频率和设备,用于确定共振频率

    公开(公告)号:EP1748674A4

    公开(公告)日:2008-05-07

    申请号:EP05737289

    申请日:2005-04-26

    Applicant: TOA CORP

    CPC classification number: H04R29/007 H04R27/00

    Abstract: The resonance frequency of a magnified-sound space is determined based on a basic amplitude/frequency characteristic obtained by sound magnifying, from a speaker (13) located in the magnified-sound space (40), a predetermined measurement signal and then receiving the sound by use of a microphone (14) located in the magnified-sound space (40); also based on a first amplitude/frequency characteristic obtained by sound magnifying, from the speaker (13), the measurement signal and a first delayed signal, which is obtained by delaying an output signal from the microphone (14) by a first delay time of zero or more, and then receiving the sound by use of the microphone (14); further based on a second amplitude/frequency characteristic obtained by sound magnifying, from the speaker (13), the measurement signal and a second delayed signal, which is obtained by delaying an output signal from the microphone (14) by a second delay time of zero or more, and then receiving the sound by use of the microphone (14). The second delay time is different in value from the first delay time.

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