RESUMO
The advent of Cochlear Implants (CI) has bought with it, the goal of spoken language performance for severe-profound sensori-neural hearing loss (SNHL) as par with the normal hearing listeners. The aim of this study was to evaluate the outcome of paediatric cochlear implantation in auditory and speech skills below the age of 5 years. The present study consisted of 50 childrens. Auditory skills were assessed in terms of audiometric thresholds and localization abilities. Speech - Language skills were measured using; Categories of Auditory Performance -CAP; Meaningful Use of Speech Scale - MUSS; Meaningful Auditory Integration Scale - MAIS and Speech intelligibility Rating - SIR. Hearing thresholds obtained from all the subjects for pre implant and post implant conditions of 3rd, 6th, 9th, 12th month conditions, evidenced a high significant (p < 0.001) improvement across all test frequencies 500, 1000, 2000 and 4000 Hz. There was also a statistically significant difference across successive measurements of auditory and speech skills, as determined by ANOVA (F (4, 245) = 151.33, p < 0.001 for CAP; F (4, 245) = 89.636, p < 0.001 for SIR; F (4, 245) = 812.282 p < 0.001 for MAIS and F(4, 245) = 435.677 p < 0.001 for MUSS). Auditory localization abilities were also improved considerably over a period of one year. The present study added the evidence to the literature that cochlear implants significantly improved the hearing ability of children with severe-to-profound hearing loss. This study also demonstrated that, children were better able to make use of the auditory information perceived through the implant.
RESUMO
Auditory feedback plays an important role in phonatory control. When auditory feedback is disrupted, various changes are observed in vocal motor control. Vocal intensity and fundamental frequency (F0) levels tend to increase in response to auditory masking. Because of the close reflexive links between the auditory and phonatory systems, it is likely that phonatory stability may be disrupted when auditory feedback is disrupted or altered. However, studies on phonatory stability under auditory masking condition in adult subjects showed that most of the subjects maintained normal levels of phonatory stability. The authors in the earlier investigations suggested that auditory feedback is not the sole contributor to vocal motor control and phonatory stability, a complex neuromuscular reflex system known as kinaesthetic feedback may play a role in controlling phonatory stability when auditory feedback is disrupted or lacking. This proposes the need to further investigate this phenomenon as to whether children show similar patterns of phonatory stability under auditory masking since their neuromotor systems are still at developmental stage, less mature and are less resistant to altered auditory feedback than adults. A total of 40 normal hearing and speaking children (20 male and 20 female) between the age group of 6 and 8 years participated as subjects. The acoustic parameters such as shimmer, jitter and harmonic-to-noise ratio (HNR) were measures and compared between no masking condition (0 dB ML) and masking condition (90 dB ML). Despite the neuromotor systems being less mature in children and less resistant than adults to altered auditory feedback, most of the children in the study demonstrated increased phonatory stability which was reflected by reduced shimmer, jitter and increased HNR values. This study implicates that most of the children demonstrate well established patterns of kinaesthetic feedback, which might have allowed them to maintain normal levels of vocal motor control even in the presence of disturbed auditory feedback. Hence, it can be concluded that children also exhibit kinaesthetic feedback mechanism to control phonatory stability when auditory feedback is disrupted which in turn highlights the importance of kinaesthetic feedback to be included in the therapeutic/intervention approaches for children with hearing and neurogenic speech deficits.
RESUMO
Cochlear implantees have considerably good speech understanding abilities in quiet surroundings. But, ambient noise poses significant difficulties in understanding speech for these individuals. Bimodal stimulation is still not used by many Indian implantees in spite of reports that bimodal stimulation is beneficial for speech understanding in noise as compared to cochlear implant alone and also prevents auditory deprivation in the un-implanted ear. The aim of the study is to evaluate the benefits of bimodal stimulation in children in an Indian cochlear implant clinic. A group of 14 children who have been using cochlear implants served as subjects in this study. They were fitted with advanced digital hearing aids in their un-implanted ears to provide bimodal stimulation. Results revealed that bimodal stimulation did not bring greater change in speech scores in quiet surroundings but have shown a noticeable improvement in noisy ambience. Hence the present study suggests that bimodal stimulation would benefit children with cochlear implants especially in adverse listening conditions.
