A robust and accurate cross-correlation-based fundamental frequency (F/sub 0/) determination method for the improved analysis of infant cries

The extraction and analysis of the fundamental frequency (F/sub 0/) of infant vocalizations has been the focus of a number of efforts over the past thirty years. It is thought that this parameter is an important information channel from which information regarding the state of an infant can be determined. To date, research groups working to extract the vocal fundamental frequency of infant cries have been limited in the resolution and granularity of the F/sub 0/ extraction methods used for adult speech, which, typically are not well suited for infant cries. In general, the fundamental frequency range of adult speech is limited to values below 600 Hz, whereas for infant cries, F/sub 0/ can have a range of several kilo hertz, and be subject to rapid changes in certain cases. This paper presents a new method for accurately determining the F/sub 0/ of infant cries, which should be applicable to other vocalizations as well. The method presented uses the crosscorrelation of adjacent speech segments to generate a three-dimensional plot called a crosscorrelogram. From this plot, the fundamental frequency of an infant cry can easily be extracted, with increased precision.