摘要 |
Methods and techniques to implement a digital signal processor for avoidance of audio feedback are disclosed, in particular, audio signal processing systems that reduce the requirement for physical segregation of sound acquisition and diffusion zones. In a more general aspect, the components and techniques described herein provide a for a sound space and sound processing equipment such that sound travelling electronically in a loop through the sound processing equipment that is output into a physical sound diffusion zone, received at the input to the sound processing equipment, and then re-amplified, etc. is attenuated over that loop by frequency modification. The frequency modification is such that, at least for some signals, on each pass through the loop, the sound processing equipment will attenuate or amplify individual sub-bands of the frequency spectrum of the audio signal that is received at the input of the sound processing equipment. The frequency range of each individual sub-band is modified as it passes through the sound processing equipment, transformed into sound in the physical space, picked up again by the sound processing equipment, and then passes through again, so that the sub-band is attenuated on at least one of those passes through the sound processing equipment. The attenuation can be performed by configuring the sound processing equipment to amplify some input frequencies and shift those frequencies to other frequencies that the sound processing equipment is configured to attenuate.
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