Longitudinal follow-up of hearing, speech, and language skills in 6-year-old children with congenital moderate hearing loss

Objectives: Children born with moderate hearing loss present with speech and language outcomes at both ends of the spectrum. To explore reasons for this, the objective of this study was to follow up a group of children born with moderate sensorineural hearing loss at 6 years of age (n = 7) by investigating their outcomes in hearing, speech, and language development from time point of hearing aid fitting at 6 months. Another objective was to investigate the relationship between earlier outcomes on precursing variables to the current status in auditory, speech and language development. Method: Earlier data from a project with the same participants of auditory variables, speech, and language development were compared to the current study outcomes at 6 years of age. Children in this study performed standardized tests of phonology (SVANTE), expressive vocabulary (BNT), and speech-in-noise test (Hagerman's sentences). Parents reported on their child's functional auditory performance in everyday life (PEACH), and demographics and general development (questionnaire). Etiology and frequency of speech and language-directed intervention from time point of diagnosis to 6 years of age were collected through medical journals. Results: Hearing levels were stable over time in all children but one, who had received bilateral cochlear implants. Performance on speech-in-noise testing varied in aided condition (-0.8 to 8, mean 2.65, SD 3.09) and unaided condition (7.2 dB-21.2 dB, mean 12.06, SD 4.82). Scores on the PEACH indicated further review in four of the seven children. Mean group score on consonant proficiency had increased from 3 to 6 years of age and were within age norms. Vocabulary scores were below the norms of children with typical hearing. Outcomes on vocabulary measures at 2.5 years showed strong correlations that were significant to scores on the BNT at 6 years of age (r = 0.87, p = 0.05). Correlations between hours of hearing aid use and vocabulary was not significant at 6 years of age. The frequency of intervention sessions in the first 6 years varied between participants (4-55, mean 19.1, SD 17.1). Conclusion: Despite homogeneous hearing and other background variables in the participants from birth, large individual variations in speech and language outcomes at 6 years of age were found. Considering the many factors involved that impact the development of children with moderate hearing loss, the results suggest that monitoring early precursors in auditory, speech and language development may be helpful in setting commensurate goals for each child. Detecting additional conditions that may pose challenges in future speech and language as early as possible is important. There is ample room for improvement in terms of increasing the frequency of intervention for children with moderate hearing loss and their families.