The acoustic analysis of voice onset time in cochlear implanted children and normal-hearing controls

Transcription

1 Audiol. 2010;19(1): Research Article The acoustic analysis of voice onset time in cochlear implanted children and normal-hearing controls Rahimeh Roohparvar 1 - Dr. Mahmood Bijankhan 1 - Dr. Saeed Hasanzadeh 2 - Dr. Shohreh Jalaie Department of General Linguistics, Faculty of Literature and Humanities, University of Tehran, Iran 2 - Department of Psychology and Education of Exceptional Children, Faculty of Psychology and Education, University of Tehran, Iran 3 - Department of Biostatistics, Faculty of Rehabilitation, Tehran University of Medical Sciences, Iran Received: 22 July 2009, accepted: 22 November 2009 Abstract Background and Aim: Hearing has an important role in speech production and making phonological distinction, especially voicing distinction. Voice onset time (VOT) has been a reliable acoustic cue of voicing differences in plosive consonants. The purpose of this study was to measure VOT in initial Persian (Farsi) oral plosives produced by cochlear implanted children, comparing to normal hearing children. Methods: In this cross-sectional study, 20 cases and 20 controls were assessed. Cases were prelingually deaf children who were cochlear implanted 4.5 years prior to test. Controls were normal hearing children at 4.5 years of age. VOT were measured while children uttered oral plosives. The effect of hearing status, voicing, and gender on VOT were assessed. Results: The amount of VOT of plosives produced by girls was higher than boys, in both groups. This difference was significantly higher in voiceless plosives than in voiced ones. In both groups, voiceless plosives had long-positive VOT value; while the amount of VOT was short-positive regarding voiced plosives. Conclusion: It was demonstrated that VOT is significantly correlated with voicing. In voiceless plosives, VOT could not be considered as a phonetic correlate of hearing status; whereas it made significant differences between cochlear implanted children and hearing controls. Furthermore, it was confirmed that concerning voiceless plosives, the amount of VOT of girls was significantly higher than boys. On the contrary, in voiced plosives, gender had no significant effect on the amount of VOT. Keywords: Cochlear implant, deaf, acoustic, Voice onset time, voicing Corresponding author: Department of General Linguistics, Faculty of Literature and Humanities, University of Tehran, Enqelab St., Tehran, , Iran. Tel: , rohparvar@ut.ac.ir

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10 * (% + # ##! "# $%&' ()' 48 2= ''. C4!O7 / G C$C4>/ 2>3 2 r;4 4 4' C$C4>/ 4 A' 4l 4 `J" 4 G E2" 27 G4.2 C4!O7 / C4' <3# 4 2A2.2" $27!2" 2" <M J"' '' 2'' 2 2$ {2 2"? 4' C$C4>/ $2& 2$% G E2" 27!2" 2" <M J"' -C42>/ 4 $ 4 A'?M 4 `J" 4!O7 / 2>3 4!O7 / ]!=. G E" 7 G C$ -C4>/ 4 H$ 4' C$C4>/ 4 H$ A8 3.'7 $& % $% 4 G E" 7 47 G C$ C2$% %2 2" <M J"' C$% C$A7 C C$A%N3.!" 42%/ 2? JO2L 2; J2= 4 k!7 C$64 >3. 4U A= 47 " <M J"' ''?)+D!R! <'7 %e7!'4' iå7 A' A.3 CU8 C$N #e7 %' CU8 B3A 3 <M J"'.!o#$ '7 A#YN H 4' AO#=7.3?M J=A 8 %e7 C$ 78 Je '' 7# > C "A##l C4#$."7 7 A>% 4 >!M 3 A J; >!M Ci 4N K % >3 4n!7A C? JU A!3 C i " dlm $84 6O4 C >!M 3 i. 7 F% n% ' 4YA.3!.(27)37 r;4 4." 'T7 N % àw7 N 4 G E"? 4 G E" 7 F%7 J!= K % VW.= i4< { 4N C4>/ C$:#$ <7 >$.3q8 3= 4 A' (28)@:4 i àw7 N 4' C C$:#$ G E" 7 G C$C4>/ 4 4' C$C4>/ K 7.J J3 4.J % 'T7 N 4 G E" 7 F%7 47.3q8 3= 4 J!= c?7 Aj A' A%N A>% 8 C$C4>/ !O7 VW G E" 7 F%7 4 J!= /.3!.J z%7 V C4 G 4' u%:7 C$ 4.J > C4 G E" 7.; F A' J " A%N > < 3$@$B&.(2926)4 r;4!3 J!= G E" 7 F%7?-@!2" 2" <2M J2"' 2'' $ 4 2 2$C42>/ 2 G2 3 4'!O3 C4' C$/ JO2L ~ T2VW G E" 7 F%7 <7 4 2!2" 23 2" 3!2" <2M J2"' 2!O3 3!" REFERENCES 1. Chin SB. Aspects of stop consonant production by pediatric users of cochlear implants. Lang Speech Hear Serv Sch. 2002;33: Hasanzadeh, S. Psychology and education of deaf children. Tehran: Samt; Lane H, Wozniak J, Perkell J. Changes in voice-onset time in speakers with cochlear implants. J Acoust Soc Am. 1994;96(1): McCrea CR, Morris RJ. Effects of vocal training and phonatory task on voice onset time. J Voice. 2007;21(1): Klatt DH. Voice onset time, frication, and aspiration in word-initial consonant clusters. J Speech Hear Res. 1975;18(4), Eilers RE, Morse PA, Gavin WJ, Oller DK. Discrimination of voice onset time in infancy.

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