- Alexander I. Rudnicky, A. Waibel, N. Krishnan. 1981. Using zero crossing counts to provide discriminative information in isolated word recognition. Abstract: Template matching systems that use a purely spectral representation are potentially insensitive to some important phonetic dimensions of speech. For example, [PI] is often confused with both [BI] and [TI] because the necessary vocalic—aspirated—fricative discrimination cannot be reliably made on the basis of spectrum alone. The zero crossing count is known to contain sufficient information for this and for other discriminations. We evaluated the usefulness of the zero crossing count in a set of experiments that used a highly confusable subset of the alpha‐digit vocabulary (3, b, c, d, e, g, p, t, v, z). In these experiments, a zero crossing count was added to a 15 coefficient spectral representation and the resulting vector was used to calculate frame distances within a dynamic warping algorithm. Testing over a corpus of 800 utterances (eight talkers), we achieved a 10% reduction in error rate. In order to obtain optimal improvement, the count had to be clipped to a restricted range, quantized to a small ...
