Methods for separating adjacent sounds with the same manner of articulation

Abstract

A difficult problem in automated time alignment is the separation of neighboring sounds with the same manner of articulation, such as two adjacent vowels or two adjacent fricatives. Usually, a broad classifier will find only one region that contains both sounds. In this study, the automatic detection of acoustic events that separate such sequences is investigated. For example, an algorithm based on abrupt changes in the energy between 2000 and 4000 Hz separates /v/’s and /š/’s, which are adjacent to /(hooked schwa)/’s or /s/’s Preliminary results based on 38 cases of adjacent fricatives taken from the TIMIT database show that 68% of the automatically placed boundaries agreed with the labeled boundaries. Of the remaining 12 cases, 67% were considered to be as good as, or even better than the TIMIT labeling. The fricative separation algorithm is presently being refined and tested across a larger database containing other similar sounds. Methods for separating adjacent stops and adjacent vowels will also be presented.