Sixth International Conference on Spoken Language Processing
October 16-20, 2000
Farsi Vowel Compensatory Lengthening: An Experimental Approach
Tehran University, Faculty of Letters and Humanities, Linguistics Dept.
Research Center of Intelligent Signal Processing, Iran
This paper addresses a question concerning phonological
operations involved standard Farsi vowel Compensatory
Lengthening (CL) due to glottal consonant deletion in syllabic
coda. Specifically, I question two current views related to CL
process. One view suggests that glottal allophonic weakening is
compensated by vowel lengthening. Another view suggests that
glottal consonant is deleted, but vacated mora is filled by
preceding vowel. Based on an experimental approach, I claim
that Farsi CL is a gradient process in which different magnitude
of glottal gesture variation is accompanied by F0 decreasing of
vowel onset and offset and lengthening of the vowel. Evidence
for this claim comes from the results of two experiments. For
experiment 1, ten sentences having ten CaC words were made.
/a/ duration was doubled while each synthetic CaaC word
supposed to be a phonetic counterpart of another CaCC lexical
word. Ten other sentences were generated by such CaaC words.
Ten subjects listened to these twenty sentences. Subjects’
lexical ambiguity to understand CaC and CaCC words was
37.8%. For experiment 2, subjects colloquially uttered those
twenty sentences with CaC and CaCC words. I found that, in
addition to significant vowel lengthening for colloquial CaCC ,
/a/ onset and offset F0 was significantly decreased, while
different magnitude of glottal gesture was realized in speech
signal from a weak through complete deletion of glottals. This
finding can be used to improve Farsi ASR and TTS systems.
Bijankhan, Mahmood (2000):
"Farsi vowel compensatory lengthening: an experimental approach",
In ICSLP-2000, vol.2, 507-510.