Patent ID: 8489404

Claim:
A method for time scale modification of an audio signal, comprising: receiving an audio signal; separating the audio signal into a plurality of frames; obtaining at least one time domain feature of each of the frames, including: segmenting the frames into a plurality of sequential equal length segments; and computing an average signal energy of the segments and an average zero-cross rate (ZCR) of the segments, wherein the at least one time domain feature includes the average signal energy and the average ZCR; analyzing a current frame of the plurality of frames to detect a transient, wherein said analyzing comprises comparing the at least one time domain feature of the current frame with a predetermined value, wherein if the time domain feature is greater than the predetermined value, the frame is determined to include a transient, wherein the predetermined value comprises the average signal energy of a previous segment and the average ZCR, wherein if an energy difference of a current segment exceeds the average signal energy of the previous segment then the current frame containing the current segment is determined as including a transient, and if the ZCR of the current segment exceeds the average ZCR, the current frame containing the current segment is determined as including a transient, and wherein the average ZCR is regulated by multiplying the average ZCR with an adaptive coefficient; processing the plurality of frames, wherein frames that do not include a transient are time scale modified and frames that include a transient are not time scale modified; and outputting the processed frames.