Audiologic-Acoustic Evaluation of Speech Perception in Children with Cochlear Implants

Abstract

An early diagnosis of the congenital disorder of hearing creates new challenges for a multidisciplinary team: paedoaudiologists, ear nose throat specialists, and speech therapists. The cross modality matching method is based on the objective and subjective techniques in the evaluation of hearing thresholds in children. The electrical response audiometry provides information about the response of the brainstem to acoustic stimulation; the behavioural audiometry gives information about the perception and central associative processes in the auditory pathway. The paediatric fitting procedure relies on solid foundations of behavioural measurement to ensure the validity of hearing aid and cochlear implant fitting. This study assessed perception of phonemes in children with the cochlear implants and possibilities of applying acoustic solutions to the audiologic evaluation. The authors have also examined the possibilities of applying digital audio processing algorithm in clinical practice. Self-developed computer controlled diagnostic stations were used and tested. Speech perception was assessed on the basis of Erber’s categories. Detection, discrimination and identification tests of 5 Ling phoneme were used. The sample comprised 23 implanted children, aged 3–6 years, who received a cochlear implant when they were 18 to 30 months old. The detection thresholds, discrimination and identification scores were assessed. Tests based on phonemes aa, uu, ii, ss, and sh (5 sounds of Ling) were used. The results indicated significant correlations between pure tone audiometry results and the thresholds of phoneme detection [dB SPL]. The identification score in this group was 95–100%.