An audio signal generation apparatus for generating an output audio waveform signal comprising:
- memory interface circuitry adapted to communicate with a memory storing original waveform data;
- a plurality of channels, each channel including;
- a sample counter adapted to perform counting operation at a given rate per sampling time period, and
- a read circuit adapted to retrieve a sample value of an original waveform from the memory through the memory interface circuitry based on a count value of the sample counter,
- each of the channels being configured to generate a waveform sample value based on the sample value of the original waveform retrieved via the read circuit of the channel so that the waveform sample value for one sample is output from the channel per sampling time period, wherein the sampling time period is a sampling time period for digital/analog conversion of the output waveform sample value;
- control circuitry configured to set, independently for each of the channels, the rate and an initial value for the sample counter of the channel and control start and stop of the counting operation of the sample counter, so that a partial portion of the original waveform corresponding to a count range from the set initial value to a count stop point is reproduced in the channel;
- an overlap adder controlled by said control circuitry and configured to output a result of addition for one sample per sampling time period;
- and
- a sound system for outputting the output audio waveform signal based on said result of addition for one sample per sampling time period output from said overlap adder,
- wherein said control circuitry is configured to set the initial values in individual ones of a set of channels, selected from among the plurality of channels, such that sample values at different sample positions of the original waveform are retrieved from the memory in individual ones of the set of channels, and control said overlap adder to add up a plurality of waveform sample values generated in the set of channels in the same sampling time period, whereby sample values of an audio waveform signal with a plurality of partial portions of the original waveform, which are to be reproduced in the set of channels, partially overlapping each other are output from said overlap adder as results of addition over a plurality of the sampling time periods output from said overlap adder,
- wherein the given rate, the initial values, and the plurality of partial portions of the original waveform are determined on the basis of at least one of a first rate for performing stretch/compression control on a reproduction time length, a second rate for controlling a reproduction pitch of an audio waveform signal to be reproduced in the set of channels, and a third rate for controlling a formant, and
- wherein the control circuitry is configured to set a reproduction start time difference between two adjacent partial portions of the plurality of partial portions of the original waveform so that a pitch of the output audio waveform signal is adjusted from an original pitch of the original waveform into the reproduction pitch based on the second rate.