Speech perception outcomes after cochlear implantation in prelingually deaf infants: The Western Sicily experience

Abstract

Objectives: To describe audiometric characteristics and speech perception performances of prelingually deaf Sicilian children after cochlear implantation; to identify the influence of cochlear implant (CI) user and family's characteristics on speech recognition and intelligibility outcomes. Methods: Twenty-eight infants with a congenital or acquired hearing impairment and implanted before the 3rd year of life were studied; all children suffered from bilateral sensorineural hearing loss (SNHL) with evidence of lack of hearing aids benefit and no evidence of intellectual disability. The study of the main characteristics associated with CI user and family's profile was performed with a clinical assessment including pre-implant and post-implant (1, 3, 6, 12 and 18 months) behavioural audiometry (evaluating average threshold for the frequencies 0.5, 1, 2 and 4 KHz) and speech recognition tests (IT-MAIS, MUSS, CAP and SIR). Results: Our cohort was characterized by an early diagnosis of SNHL (5.77 and 12.17 months for congenital and acquired HL respectively), a short length of deafness (average = 6.78 months) and an implantation before the 3rd year of life (mean = 24.25 months; range from 10 to 36). Analysis of audiometric threshold revealed a significantly improved capacity to detect sounds within the conversational speech spectrum after 12 months from implantation (r = 0.99; p < 0.001). The main speech recognition test evidenced speech perception and speech intelligibility performances (CAP median value of 3; SIR category = 3 in 46.42%) equal to those children with same characteristics reported by literature. With the exception of 'daily CI use' (p < 0.001), none of the variables associated with CI user and family's profile resulted significant predictor of speech perception improvement. Conclusions: This work demonstrates that all children of our cohort, with an early diagnosis of SNHL and a CI surgery performed before the 3rd year of life, presented a progressive audiometric and speech improvement through the first 12-18 months after cochlear implantation. The study also highlights that, differently from the others variables studied, a continuous CI use influences significantly speech perception and recognition outcomes.