Method and system for tone detection

摘要

A method and system for tone detection is described. The method includes receiving a series of frames having a signal containing a tone and locating a first frame in the series of frames in which there is at least a partial tone. The signal energy of the first frame in which there is at least a partial tone may then be compared to the signal energy of a full tone frame or compared to the signal energy of a frame subsequent to the first frame in the series of frames. A start time of the tone in the signal may then be determined based on the comparison of the signal energies of the first frame and the full tone frame or subsequent frame. An end time of the tone in the signal may be determined by locating a last frame in the series of frames in which there is at least a partial tone and comparing the signal energy of the last frame in which there is at least a partial tone to the signal energy of a full tone frame or the signal energy of a frame preceding the last frame in the series of frames. The duration of the tone signal may be determined based on the determined start time and end time of the tone in the signal.