Sound modification employing spectral warping techniques

A method of applying a transformation to a digital audio signal comprising the steps of:

• capturing a frequency domain representation of successive time segments of said digital audio signal, defining a plurality of frequency domain representations each of which includes a plurality of bins, with each of said plurality of bins having a complex value associated therewith comprising a first magnitude and a first phase;
• modifying said first magnitude of a first selected bin of said plurality of bins while preserving said first phase of said first selected bin by using the bin number of said first selected bin as an index to a look-up table that provides a second bin number of a second selected bin having a second magnitude to be used to replace said first magnitude of said first selected bin;
• repeating said modifying step for a plurality of selected bins of said plurality of bins;
• and
• converting said digital audio signal into an analog audio signal in an digital-to-analog converter.

A signal processing system configured to process a digital audio signal comprising:

• a processing unit;
• and
• a memory holding digital data corresponding to said digital audio signal;
• said memory storing code to be operated on by said processing unit, said code including means for capturing a frequency domain representation of a first time segment of said digital audio signal, said frequency domain representation comprising a plurality of bins, each said bin holding a complex value having a first magnitude and a first phase;
• means for modifying said first magnitude of a first selected bin of said plurality of bins while preserving a phase of said first selected bin by using a bin number of said first selected bin as an index to a look-up table that provides a bin number of a second selected bin holding a second magnitude to be used to replace said first magnitude of said first selected bin;
• and
• a digital-to-analog converter for converting said digital audio signal into an analog audio signal.

A computer program product that controls a computer to transform a digital audio signal, comprising:

• code to capture a frequency domain representation of a first time segment of said digital audio signal, said frequency domain representation comprising a plurality of bins, each said bin holding a complex value having a first magnitude and a first phase;
• and
• code to modify said first magnitude of multiple selected bins of said plurality of bins by using a bin number of said multiple selected bins as an index to a look-up table that provides bin numbers of additional selected bins holding a second magnitude to be used to replace said first magnitude of said multiple selected bins;
• wherein said modified digital audio signal is converted into an analog audio signal in a digital-to-analog converter.