The simulation of many apparent similar sound sources occuring nearly in unison from a single, actual source is referred to as a chorus effect.
The chorus effect is achieved by applying various independent modifications to multiple copies of a given input signal and summing them together to create the output signal.
Signal modifications can include delay, frequency shift, and/or amplitude changes.
Time-varying delay lines can simulate changes in delay and frequency shift.
A single multi-tap interpolating delay line with modulated ouput tap locations can efficiently and effectively implement the chorus effect.
The following MSP patch implements a chorus effect. Better results can be achieved with more “copies” of the input signal.
The rand˜ MSP object produces interpolated noise at a subsampled rate, as specified by the input argument. This provides a noise like signal with energy only at frequencies below this rate.