Tense/lax vowel classification usin

In English, the feature [tense] or [ATR] (advanced tongue root) has been used to encompass the vowels that are produced on the extreme edges of the acoustic and articulatory spaces. The lax counterparts to these vowels are generally produced closer to the center of those spaces. The present study is based on the hypothesis that the extreme positioning in both articulatory and acoustic space evolves during the course of vowel production. This study uses two measures that attempt to track these changes over time. The dataset consists of 48 citation-form vowels in stressed position, from each of three male speakers, (144 total). The slope of the first formant movement across the vowel distinguished between tense and lax vowels with a 90% accuracy. The location in time of the energy peak in the first formant region as a percentage of vowel duration classified the vowels with an 83% accuracy.