Investigation of speech and voice characteristics in Turkish-speaking post-lingual cochlear implant users

Along with hearing loss; disruptions occur in the auditory feedback mechanism of the speech chain. While the speaker can listen to his voice simultaneously with speech and control his voice, articulation and general comprehensibility, the disruption of the auditory feedback mechanism will affect the acoustic properties and comprehensibility of the sound. In postlingual CI individuals, previously existing auditory feedback has been impaired after language acquisition and auditory feedback is improved with cochlear implant. The sample of the study consists of 21 postlingual CI users and 21 normal hearing adults. Objective and subjective evaluations were made to examine the sound and speech characteristics of the participants. In addition, the effects of factors such as implant usage time, gender, age on sound and speech characteristics were examined. In addition, the effects of factors such as implant usage time, gender, age that will affect voice and speech characteristics were examined. In acoustic sound analysis; fundamental frequency (F0), Jitter (%), Shimmer (%) and HNR (Harmonic Noise Ratio) parameters were examined.Although there were disruptions in these parameters, they were not statistically significant. For the purpose of perceptual evaluation, GRBAS evaluation was performed by two experts and it was found that the average scores of Grade (Dysphonia degree)2 were statistically significantly higher in the patient group (0.95±0.87) (p<0.05). The average ranks of Breathiness2 parameter were also found to be statistically significantly higher in the patient group (Rank avg:25.10) (p<0.05). For the purpose of evaluating their own voices, the participants were administered the Speech Handicap Index-10 (SHE-10), and for the purpose of evaluating the speech intelligibility of the person by their communicators, the Connected Speech Intelligibility Scale (CSIS) was also administered. The average scores of SHE-10 were found to be statistically significantly higher in the normal group (8.24±7.95) (p<0.05). The average ranks of CSIS were also found to be statistically significantly higher in the normal group (Rank avg:29.81) (p<0.05). The correlation between cochlear implant usage time, gender and age characteristics and the results was examined but was not found to be statistically significant. When all data is considered, although cochlear implant usage significantly improves auditory feedback and brings speech characteristics closer to normal levels for individuals with post-lingual hearing loss, it is deemed insufficient and needs to be supported by auditory rehabilitation and speech therapy.