Method and system for playing audio at an accelerated rate using multiresolution analysis technique keeping pitch constant

A signal processing unit for playing back an audio signal at an accelerated rate comprising:

• a plurality of bandpass filters receiving a first plurality of samples of the audio signal, said plurality of bandpass filters configured to generate a second set of plurality of samples after passing the first plurality of samples of the audio signal through each of them;
• a plurality of decimators connected to at least one bandpass filter of the plurality of bandpass filters, said plurality of decimators configured to generate a third set of plurality of samples;
• and
• an adder configured to superimpose constituents of the third set of plurality of samples generated by the plurality of decimators on a sample by sample basis,
• wherein the adder outputs a fourth plurality of samples which when played generates an accelerated version of the audio signal having a pitch which is consistent with a pitch of the audio signal in a non-accelerated condition.

A method of playing back an audio signal at an accelerated rate, said method comprising:

• providing a plurality of subunits connected in parallel;
• providing at least a bandpass filter and a decimator in each of the plurality of subunits;
• passing a first plurality of samples of the audio signal through the plurality of subunits, wherein the plurality of subunits are configured to generate a second set of plurality of samples after passing the first plurality of the audio signal through them;
• and
• superimposing constituents of the second set of plurality of samples, said superimposing generating a third plurality of samples, wherein playing the third plurality of samples generates an accelerated version of the audio signal having a pitch which is consistent with a pitch of the audio signal in a non-accelerated condition.