Studies of language development in children with mild-moderate hearing loss are relatively rare. Longitudinal studies of children with late-identified hearing loss are relevant for determining how a period of unaided mild-moderate hearing loss impacts development. In recent years, newborn hearing screening programs have effectively reduced the ages of identification for most children with permanent hearing loss. However, some children continue to be identified late, and research is needed to guide management decisions. Furthermore, studies of this group may help to discern whether language normalizes after intervention and/or whether certain aspects of language might be vulnerable to persistent delays. The current study examines the impact of late identification and reduced audibility on speech and language outcomes via a longitudinal study of four children with mild-moderate sensorineural hearing loss.
Longitudinal outcomes of four children with late-identified mild-moderate sensorineural hearing loss were studied using standardized measures and language sampling procedures from at or near the point of identification (28 to 41 mos) through 84 mos of age. The children with hearing loss were compared with 10 age-matched children with normal hearing on a majority of the measures through 60 mos of age. Spontaneous language samples were collected from mother-child interaction sessions recorded at consistent intervals in a laboratory-based play setting. Transcripts were analyzed using computer-based procedures (Systematic Analysis of Language Transcripts) and the Index of Productive Syntax. Possible influences of audibility were explored by examining the onset and productive use of a set of verb tense markers and by monitoring the children's accuracy in the use of morphological endings. Phonological samples at baseline were transcribed and analyzed using Computerized Profiling.
At entry to the study, the four children with hearing loss demonstrated language delays with pronounced delays in phonological development. Three of the four children demonstrated rapid progress with development and interventions and performed within the average range on standardized speech and language measures compared with age-matched children by 60 mos of age. However, persistent differences from children with normal hearing were observed in the areas of morphosyntax, speech intelligibility in conversation, and production of fricatives. Children with mild-moderate hearing loss demonstrated later than typical emergence of certain verb tense markers, which may be related to reduced or inconsistent audibility.
The results of this study suggest that early communication delays will resolve for children with late-identified, mild-moderate hearing loss, given appropriate amplification and intervention services. A positive result is that three of four children demonstrated normalization of broad language behaviors by 60 mos of age, despite significant delays at baseline. However, these children are at risk for persistent delays in phonology at the conversational level and for accuracy in use of morphological markers. The ways in which reduced auditory experiences and audibility may contribute to these delays are explored along with implications for evaluation of outcomes.
This prospective, longitudinal study examined speech and language outcomes of four children with late-identified, mild-moderate, sensorineural hearing loss, compared to 10 children with normal hearing. Purposes of the study were to determine the degree to which initial delays resolved over time, and whether phonology and morphology were vulnerable to persistent delays. Results of standardized measures showed that initial delays resolved by five years of age for three of the four children. However, persistent delays were observed in phonology and accuracy of morpheme use. Ways that auditory experience and audibility may contribute to susceptibility in these areas of development are discussed.
Boys Town National Research Hospital, Omaha, Nebraska.
Address for correspondence: Mary Pat Moeller, PhD, Boys Town National Research Hospital, 555 N. 30th Street, Omaha, NE 68131. E-mail: email@example.com.
Received July 15, 2009; accepted March 11, 2010.