Patent ID: 7415416
Filing Date: 2008-08-19
Classification: G03B,H04N

Abstract:
1. An apparatus for controlling a device, the apparatus comprising: a receiver operable to receive a speech signal; a divider operable to divide the speech signal into a sequence of speech frames, each speech frame representing a time portion of the speech signal; a processor operable to determine an auto-correlation function for each speech frame; a peak determiner operable to locate a maximum auto-correlation value within a predetermined part of said auto-correlation function for each speech frame; a periodicity measurer operable to determine a periodicity measure of each speech frame by using the maximum auto-correlation value of each speech frame; a variability measurer operable to determine, from periodicity measures of a plurality of consecutive speech frames, a plurality of variability measures by using different calculation methods; a detector operable to combine the plurality of variability measures and to detect an extended periodic portion from the combined variability measures; and a controller operable to control said device in dependence upon a detection made by said detector.