Patent ID: 7120575
Filing Date: 2006-10-10
Classification: G10L

Abstract:
1. A method for the segmentation of an audio stream into semantic or syntactic units wherein the audio stream is provided in a digitized format, comprising the steps of: determining a fundamental frequency for the digitized audio stream; detecting changes of the fundamental frequency in the audio stream, wherein detecting the changes of the fundamental frequency includes providing a threshold value for estimates of the fundamental frequency's voicedness and determining whether the voicedness of the fundamental frequency estimates are higher or lower than the threshold value, and wherein the voicedness of the fundamental frequency estimates lower than the threshold value equals no voice, and wherein the voiceness of the fundamental frequency estimates higher than the threshold value equals voice; determining candidate boundaries for the semantic or syntactic units depending on the detected changes of the fundamental frequency; extracting a plurality prosodic features in an environment of the audio stream where the voicedness of the fundamental frequency estimates are lower than the threshold value, wherein the environment is a period of time between 500 and 4000 milliseconds preceding and following the candidate boundaries; combining the plurality of prosodic features; and determining boundaries for the semantic or syntactic units depending only on the combined plurality of prosodic features.