Reverberation imparting apparatus

Abstract

A reverberation imparting apparatus comprises at least a data shift register, a coefficient shift register and an arithmetic convolution unit. The data shift register stores a string of sampling data each representative of an instantaneous value of an audio signal at each sampling period, while the coefficient shift register stores a string of coefficients which are created on the basis of waveforms of reflected sounds in response to an impulse sound artificially produced in a certain sound-field space such as a church. Normally, the data shift register successively stores new sampling data which are newly inputted thereto so that the contents of the data shift register is successively renewed. The arithmetic convolution unit performs an arithmetic convolution, using the string of coefficients on the string of sampling data. However, when an amplitude level indicated by the sampling data becomes lower than a threshold level, the data shift register prohibits the new sampling data from being stored therein, so that the string of sampling data stored are fixed. In addition, the coefficients stored are successively shifted from relatively-old coefficients, which are produced responsive to relatively-old waveforms of reflected sounds, to relatively-new coefficients which are produced responsive to relatively-new waveforms of reflected sounds. Hence, the arithmetic convolution unit performs the arithmetic convolution, using the coefficients which are successively shifted, on the fixed string of sampling data. Thus, it is possible to impart a long-time reverberation to the audio signal.