The Acoustic Characteristics of the Voice in Cochlear-Implanted Children: A Longitudinal Study

Objective. The purpose of this study was to characterize changes in the voice and vowel articulation of prelingually deaf children after cochlear implantation. Methods. In this study, the patient group included 30 prelingually deaf children who underwent unilateral cochlear implantation at 4-6 years of age. The control group included normally hearing children of the same age. All deaf children had follow-ups before cochlear implantation and at 1, 3, 6, 12, and 24 months after implantation. The acoustic parameters, aerodynamic parameters, and vowel formants were measured in the patient group and compared with those of the control group. Results. All acoustic parameters, aerodynamic parameters, and vowel formants differed significantly between normally hearing children and prelingually deaf children. For prelingually deaf children, all of the above parameters gradually decreased after cochlear implantation. Furthermore, the acoustic parameters Jitter and Shimmer were significantly reduced as early as 6 months, whereas the fundamental frequency, the standard deviation of fundamental frequency, estimated subglottal pressure, aF1, iF2, and uF2 were significantly altered 12 months after implantation. However, statistically significant differences in these parameters were not observed between 12 and 24 months after cochlear implantation. Conclusion. After cochlear implantation, prelingually deaf children established auditory feedback and improved voice control and vowel production.