| 摘要 |
<p>PURPOSE:To prevent a loudspeaker device from howling by measuring cross-power spectra between a loudspeaker and microphone and by processing a howling component. CONSTITUTION:An input sound to microphone 1 in sound input part 3 is radiated by way of amplifier 2, adder-subtracter 13 and speaker 5 in sound output part 6. Transfer-function measuring instrument 7 receives input and output signals of adder-subtracter 13 and measures cross-power spectra between the output signal of microphone 1 and the input signal to speaker 5 and then inputs and measured value to transfer characteristic memory 9. Arithmetic unit 11 performs the Fourier inverse transform about the power spectra from signal memory 10 and the measured value from memory 9 and generates a signal substantially equivalent to the howling component. This signal is added to and subtracted from the signal of microphone 1 by adder-subtracter 13 to remove the howling signal.</p> |
