Automatic sentential vowel stress and sentence final pitch slope labeling

Vowel stress in English is marked by pitch rise-falls, energy, and duration. After studying the stress marking strategies of 15 talkers of American English, an algorithm was devised that labels vowels in continuous speech with three levels of stress. The algorithm is based on a model for combinations of pitch rise-falls, relative energy, and duration. The pitch of voiced regions is characterized as rising, falling, or steady. Sequences of three regions are examined to find the pitch rise-fall patterns that signal stress. If the energy of the vowel is within 8 dB of the maximum in the utterance, it is considered energy stressed. Duration is corrected for pre-pausal effects. If two out of three cues are present, then the vowel is labeled stressed. The algorithm was tested on sentences of American and British English and found to perform very well. Detailed results will be presented, and performance of the final pitch slope determination will be discussed relative to a perceptually labeled database.