Acoustic pattern recognition of fricative-vowel coarticulation by the self-organizing map.

Word-initial samples of fricative [s] preceding vowels [a:], [ae:], [e:], [i:], [u:], [o:], and [y:] in Finnish words were studied with the self-organizing map. An acoustic map was first calculated from speech samples of women without speech disorders, and then the [s] samples were measured on this map. In all 10 subjects the [s] samples preceding the rounded vowels [u:] and [o:] clearly differed from the samples in front of unrounded [a:], [ae:], [e:], and [i:]. The coarticulatory phenomena observed on the map were due to changes in the composition and stability of the fricative spectrum.