A Comparison of Acoustic Charateristics of Speech in Young Cochlear Implant and BTE Users with Normal Hearing Age Matched Individuals
- Voice Onset Time (VOT),
- word and vowel duration,
- fundamental frequency (F2)
Abstract
A major consequence of hearing impairment in children appears to be a reduced repertoire of sound segments mainly consonants which results in place, manner and voicing errors leading to poor communication. With advancement in technology (cochlear implants and programmable digital behind the ear devices), significant progress have been made by children with profound hearing impairment. Cochlear implant (CI) aims to improve the speech perception and production abilities in individuals who receive limited gain from the conventional amplification devices. The primary aim of the present study was to compare selected acoustic speech parameters (lead and lag Voice Onset Time, word and vowel duration and second formant frequency) of children with hearing impairment using cochlear implants, Behind The Ear (BTE) hearing aids with those of age matched normal hearing peers. Results indicated that, the mean lead Voice Onset Time (VOT) in CI and BTE users was longer compared to normal hearing individuals, though not statistically significant. Results of lag VOT indicate that mean values for the CI and BTE groups were shorter than normal hearing individuals. Measures of F2 revealed that CI group had higher F2 where as the BTE users had lower F2 values compared to normal hearing individuals. Among the duration measures only vowel duration was significantly different between normal hearing individuals and CI. Though several studies report that acoustic measures of the speech of cochlear implantees approximate normal values, similar findings were not obtained in the present study, probably because the cochlear implantees in this study were implanted only six months prior to data collection.
References
Calvert, D.R (1961). Some acoustic characteristics of the speech of profoundly deaf individuals. Cited in Doctoral Dissertation; Stanford University.
Dawson, P., Blamey, S. J., Dettman, S. J., Rowland, L.C., Barker, E.J., Tobey, E.A.,Busby, P.A., Cowan, R.C. & Clark, G.M., (1995). A clinical report on speech production of cochlear implant users. Ear and Hearing, 16, 551-561.
Dorman, M.F., Hannley, M.T., Dankowski, K., Smith, L., & McCandless, G. (1989) Word Recognition
by 50 patients fitted with the Symbion multichannel cochlear Implant. Ear and Hearing, 10, 44-49.
Ertmer, D., Kirk, K., Todd, S., Riley, A. (1997). A comparison of vowel production of children with multichannel cochlear implants or tactile aids. Perceptual Evidence. Ear and Hearing, 18, 307- 315.
Fryauf-Bertschy, H., Tyler, R. S., Kessay, D.M .R., Gantz, B. J., & Woodworth, G.G. (1997). Cochlear implant use by prelingually deafened children: The Influence of age of implant and length of device use. Journal of Speech and Hearing
Research, 40, 183-199.
Gilbert, H. R. & Campbell. M. I. (1978): Voice onset time in the speech of Hearing impaired individuals. Folia Phoniatrica, 30, 67-81.
Hutchinson, J.M., & Smith, L.L. (1976). Aerodynamic Functioning in Consonant Articulation in Hearing Impaired Adults. Audiology and Hearing Education, 34, 16-25.
Kirk, K., & Edgerton, F., (1983). The effects of cochlear implant use on voice parameters. Symposium Inner Ear Surgery, 16, 281-292.
Kirk, K. I., Diefendorf, E., Riley, A., & Osberger, M .J. (1995). Consonant production of children with multichannel cochlear implants or hearing Aids. Advances in oto - Rhino - Laryngology, 50, 154-159.
Levitt, H., & Stromberg, H. (1983). Segmental characteristics of hearing impaired children: Factors affecting intelligibility. In I. Hochber,H. Levitt, & Osberger (1983), Speech of the hearing impaired: Research Training , personnel preparation (pp 53-74). Baltimore: University
Lisker, L, & Abramson, A.S. (1964). A cross language study of voicing in initial Stops: Acoustical measurements. Word, 20, 384-422.
Monsen, R. (1974). Durational aspects of vowel production in the speech of deaf children. Journal of Speech and Hearing Research, 17, 386-398.
Monsen, R.B. (1976). Normal and reduced phonological space : The production of English vowels by Deaf Adolescents. Journal of Phonetics, 4, 189-198.
Natraja. N. P., Sreedevi. N. & Sangeetha, M (1998), Acoustic analysis of speech of the hearing impaired, Journal of Acoustical Society of India 26,140-142.
Osberger, M. J., Robbins, A. M., Berry, S. W., Todd, S. L, Hesketh, L. J., & Sedey, (1991). Analysis of spontaneous speech samples of children with Implants or tactile aids. American Journal of Otology, 12 (Suppl.), 151-164.
Ravishankar, K.C. (1981). VOT in different age ranges. Masters Dissertation, Submitted to the University of Mysore, Mysore.
Sehgal, S. T., Kirk, K. I., Svirsky, M. A., Ertmer, D. J. & Osberger, M. J. (1998), Imitative consonant feature production by children with multichannel sensory aids. Ear and Hearing, 19, 72-84.
Shukla, R.S. (1987): Objective measurement of the speech of the hearing impaired. Unpublished Doctoral Thesis. Submitted to the University of Mysore, Mysore.
Smith, C. R. (1975). Residual hearing and speech production in deaf children. Journal of Speech and Hearing Research,18,795-811.
Tait, D. M., & Lutman, M, E. (1994). Comparison of early communicative behaviour in young children with cochlear implants and with hearing aids. Ear and Hearing, 15,352-361.
Tait, M., & Lutman, M. E. (1997). The predictive value of measures of preverbal communicative behaviours in young deaf children with cochlear implants. Ear and Hearing, 18, 472-478.
Tobey, E., Geers, A., & Brenner, C. (1994). Speech production results: Speech feature acquisition.Volta Review, 96,109-129.
Tobey, E. A., & Hasenstab, S. M. (1991). Effects of a Nucleus multichannel cochlear implant upon speech production in children. Ear and Hearing, 12, 48-54S.
Uchanski, R.M., & Geers, A.E. (2003). Acoustic Characteristics of the Speech of Young Cochlear Implant Users: A Comparison with Normal-Hearing Age- Mates. Ear and Hearing, 24, 90S-105S.
Vasantha, D (1995): Phonological space for vowel production in Telugu deaf children: A spectrographic study. Journal of Acoustical Society of India, 23, 36-47.