Abstract: A method and apparatus for marking audio data as it is recorded, and a user interface for the audio data in a computerized system, is disclosed. A recorder, such as a tape recorder, having a plurality of marker buttons is provided. The audio data is recorded on one channel of a magnetic tape. Any time one of the marker buttons is pressed, a distinct tone is recorded on another channel of the tape as a marker. The audio data and markers are then transferred to the computer system. The user interface provides a graphical display of the audio data, and provides graphical markers which correspond to the marker buttons on the recorder. The audio data can be accessed at any random point, including a point marked by a marker. Without changing modes, a user can access the data at any random point, stop play, select a new point to initiate playback and restart playback, and change the speed of playback.

Abstract: A computer implemented apparatus and method for modifying the playback rate of a previously stored audio or voice data file stored within a computer system without altering the pitch of the audio data file as originally stored. The present invention also maintains a high level of sound quality during playback. The present invention includes a double buffering system in order to perform all of the desired calculations in real time. A time stretching technique is employed upon the audio data file to decrease or increase playback rate which creates audio segments requiring joining processing. Junctions are smoothed by employing a cross-fade amplitude envelope filter and a compressor/limiter is used to maintain filter range. The system may operate on a desktop computer allowing for advantageous playback and audio data management options of stored voice and or sound data.