## 3aSC9. Evaluation of the trajectory of vowel glide based on vector analysis.

### Session: Wednesday Morning, December 4

### Time:

**Author: Jun Toyama**

**Location: Dept. of Information Eng., Faculty of Eng., Hokkaido Univ. Kita-ku, Sapporo, 060 Japan**

**Author: Masaru Shimbo**

**Location: Dept. of Information Eng., Faculty of Eng., Hokkaido Univ. Kita-ku, Sapporo, 060 Japan**

**Abstract:**

Although coarticulation frequently causes insertion and deletion errors in
speech recognition systems, human beings can recognize it correctly, presumably
because of correct estimation of glide between phonemes. The present study is
concerned with the glide characteristics of vowels, and it is shown that the
trajectory of the glide appears along geodesics calculated by the metric on a
phonetical vowel space. First the spectrum envelope of the stable part of a
vowel is digitized by representing it by a 40-dimensional vector. Then, this
vector is projected to a three-dimensional parameter space by discriminant
analysis. The trajectory of glide generally produced a curve, which suggests
that the space is non-Euclidean, as the trajectory should be the shortest path
in the space. Assuming that the distribution of each vowel is a normal
distribution, it is shown that it is an ellipsoid with a covariance matrix.
Second, by a transformation using metrics, based on the variance of vowels, the
trajectory is transformed into Euclidean space. It is shown that the transformed
trajectory of the vowel glide is a similar straight line.

ASA 132nd meeting - Hawaii, December 1996