Early language development in children with profound hearing loss fitted with a device at a young age: part I--the time period taken to acquire first words and first word combinations.

OBJECTIVE: Increasing numbers of infants and young children are now presenting to implantation centers and early intervention programs as the impact of universal newborn hearing screening programs is felt worldwide. Although results of a number of studies have highlighted the benefit of early identification and early fitting of hearing devices, there is relatively little research on the impact of early fitting of these devices on first language milestones. The aim of this study was to investigate the early spoken language milestones of young children with hearing loss (HL) from two perspectives: first, the acquisition of the first lexicon (i.e., the first 100 words) and second, the emergence of the first word combinations. DESIGN: Two groups of participants, one comprising 24 participants with profound HL and a second comprising 16 participants with normal hearing, were compared. Twenty-three participants in the HL group were fitted with a cochlear implant and one with bilateral hearing aids. All of these were "switched-on" or fitted before 30 months of age and half at < 12 months of age. Language data were collected using the Diary of Early Language, a procedure in which parents recorded their child's first 100 spoken single words and any word combinations produced while reaching this single-word target. Acquisition of single words was compared by using the time period (in days) taken to reach several single-word targets (e.g., 50 words, 100 words) from the date of production of the first word. The emergence of word combinations was analyzed from two perspectives: first, the time (in days) from the date of production of the first word to the emergence of the first word combinations and second, the size of the single-word lexicon when word combinations emerged. RESULTS: The normal-hearing group required a significantly shorter time period to acquire the first 50 (mean < 1.9 months) and the first 100 (mean < 3.9 months) words than the HL group. Although both groups demonstrated acceleration in lexical acquisition, the hearing group took significantly fewer days to reach the second 50 words relative to the first 50 words than did the HL group. Finally, the hearing group produced word combinations significantly earlier (i.e., in fewer days from production of the first word) than the HL group; however, the size of the single-word lexicon when word combinations emerged was similar for both groups. CONCLUSIONS: The results of this study suggest that despite fitting of a device at an early age, HL continues to impact early lexical acquisition and the emergence of word combinations. Further, similarities between the hearing and HL groups, such as the overall pattern of lexical acquisition and a lexicogrammatical link, suggest that the processes underpinning early language acquisition for hearing children and those with HL may also be similar.

Early language development in children with profound hearing loss fitted with a device at a young age: part II--content of the first lexicon.

OBJECTIVE: Lexical content is commonly understood to refer to the various categories of words that children produce and has been studied extensively in children with normal hearing. Unlike the hearing child, however, little is known about the word categories that make up the first lexicon of children with hearing loss (HL). Knowledge of the first lexicon is increasingly important, as infants with HL are now being detected through universal newborn hearing screening programs and fitted with hearing aids and cochlear implants in before 12 months of age. For these children, emergence of the first spoken words is a major milestone eagerly awaited by parents and one of the first verbal language goals of teachers and therapists working with such children. The purpose of this study was to evaluate the lexical content of the first 50 and 100 words produced by children with HL and to contrast this with that of a group of hearing children. DESIGN: Lexical content was compared in two groups of children: one group composed of 24 participants with severe profound or profound HL and a second group composed of 16 participants with normal hearing. Twenty-three participants in the HL group were fitted with a cochlear implant and one with bilateral hearing aids. All were "switched on" or fitted before 30 months of age. The Diary of Early Language (Di-EL) was used to collect a 100-word lexicon from each participant. All single word and frozen phrase data from each child's Di-EL were allocated to 1 of 15 word types grouped into four word categories (noun, predicate, grammatical, and paralexical), and the results were compared for both groups. RESULTS: The hearing and HL groups showed similar distributions of word categories, with nouns constituting the largest portion of the lexicon followed by predicates and paralexicals. Grammaticals made up the smallest portion of the lexicon. However, several significant differences were evident between the two groups. In both the 50- and 100-word lexicons, the hearing group used proportionately more nouns, fewer predicates, more common nouns, and fewer onomatopoeic words compared with the HL group. Further, more participants in the hearing group used grammatical word types other than adverbs (including pronouns) compared with the HL group. CONCLUSION: Overall, lexical content of the HL group was similar to that of the hearing group for both the 50- and 100-word lexicons, although some differences in proportional use were noted across word categories and types. It is suggested that differences in the quantity and diversity of language experienced by children with normal hearing compared with those with HL, together with differences in the input they receive, might in part explain these differences. The effect of quality of speech input and therapy method on the emerging lexicon and subsequent language development will be particularly important in informing appropriate intervention strategies for children with HL.

Assessment of Language Skills in Young Children with Profound Hearing Loss under Two Years of Age.

This article presents an initial evaluation of a technique known as the Diary of Early Language (Di-EL), designed to obtain data about early lexical development in young children with profound hearing loss using cochlear implants, hearing aids, or both. The validity of the Di-EL, a parent report technique, was examined through comparisons with other measures of language development. Lexical data reported by parents using the Di-EL was found to agree with that reported by the same parents for the same children using the MacArthur Communicative Development Inventories (CDI), although some differences in the lexical items were noted. Rate of lexical acquisition on the Di-EL was found to correlate highly with that measured by the CDI and with expressive language skills as measured by the Rossetti Infant Toddler Language Scale, suggesting that the Di-EL is a valid measure of early lexical progress. These results are discussed with reference to other diary studies, along with research and clinical applications of the Di-EL.