Sue Archbold

Determinants of speech perception in children after cochlear implantation

BACKGROUND Cochlear implants provide access to the speech signal in those profoundly deaf children who derive no material benefit from acoustic hearing aids. Speech perception after implantation can vary widely--we have analysed the contribution of several factors. METHODS We examined 40 children with mean age at implantation of 52 months who were either born deaf or became deaf before 3 years. All patients received the same multichannel implant system and were followed up for 5 years. We used connected discourse tracking (CDT) as the measure of speech perception. The effect of five potential predictors (age at implantation, number of inserted electrodes, origin of deafness, mode of communication, and socioeconomic group) on speech perception was analysed. FINDINGS The mean number of words per minute perceived increased from 0 before implantation to 44.8 (SD 24.3) 5 years after implantation. Repeated-measures ANOVA showed that children significantly progressed over time (p=0.001). Age at implantation was a significant covariate (p=0.01) and mode of communication was a significant between-individuals factor (p=0.04). INTERPRETATION Young age at intervention and oral communication mode are the most important known determinants of later speech perception in young children after cochlear implantation. Early identification of candidate children necessitates implementation of universal neonatal screening programmes for hearing impairment.

Categories of Auditory Performance: Inter-User Reliability

Categories of Auditory Performance (CAP) describes a scale used to rate outcomes from paediatric cochlear implantation in everyday life. It differs from more technical measures by being readily applied and easily understood by non-specialist professionals and by parents. Being based on subjective assessments, there is a need to establish whether ratings by different persons are comparable. Therefore, an analysis of inter-user reliability was undertaken using ratings from 23 children followed up at various intervals after implantation. Analysis relating scores by local teachers of the deaf and the teachers of the deaf at the implant centre revealed very high inter-user reliability (correlation coefficient 0.97). This result establishes the reliability of CAP as an outcome measure for use in cochlear implant programmes.

Reading abilities after cochlear implantation: The effect of age at implantation on outcomes at 5 and 7 years after implantation

OBJECTIVES The reading skills of deaf children have typically been delayed and this delay has been found to increase with age. This study explored the reading ability of a large group of children who had received cochlear implants 7 years earlier and investigated the relationship between reading ability and age at implantation. METHODS The reading ages of 105 children, with age at implantation less than 7 years and onset of deafness below the age of three, were assessed 5 and 7 years after implantation using the Edinburgh reading test. Net reading age was calculated by using the difference between chronological age and reading age. Non-verbal intelligence was measured for a subset of 71 children, using Ravens coloured progressive matrices. Further investigation of this subset looked at the association of nonverbal intelligence, age at implantation and reading ability. RESULTS There was a strong negative correlation at both 5 and 7 years after implant between net reading score and age at implantation. In the subset of 71 children who had an IQ score within normal range, those implanted at or before 42 months had age-appropriate reading both 5 and 7 years post-implant. This was not the case for children implanted after 42 months. Reading progress at the two post-implant assessment intervals were found to be highly related. CONCLUSIONS Age at implantation was a significant factor in the development of reading skills in this group. In children implanted below the age of 42 months, reading progress was in line with chronological age, which has not been the case previously with profoundly deaf children. With earlier implantation more common in present groups, and improved technology, there is every reason to be optimistic about the influence of cochlear implantation on the development of reading skills in deaf children.

A cost-utility analysis of pediatric cochlear implantation.

Objective/Hypothesis: The aim of this study was to explore the cost‐utility of pediatric cochlear implantation, incorporating savings associated with education into the analysis.

Cochlear implants in young children: the relationship between speech perception and speech intelligibility.

OBJECTIVE To determine the relationship between measures of speech perception and speech production after cochlear implantation of young children with profound congenital and prelingual deafness. DESIGN A prospective study was undertaken on a consecutive group of children with profound deafness. There were 126 children at the preimplantation interval and 71, 50, 26, and 20 children, respectively, at the 2, 3, 4, and 5 yr follow-up after implantation. Speech perception and speech intelligibility were assessed using hierarchical rating scales. Spearman rank correlation coefficients were used to determine the statistical correlations. All patients were either congenitally deaf or deafened before the age of 3 yr and were implanted before age 7 yr. The patients all received the Nucleus multichannel cochlear implant system with the most appropriate speech encoding strategy. RESULTS Speech intelligibility at 5 yr was strongly correlated with speech perception at the 2, 3, 4, and 5 yr intervals after implantation (Spearman coefficients 0.77, 0.81, 0.58, 0.58; p < or = 0.01). Speech intelligibility at the 2, 3, and 4 yr intervals also correlated in a similar manner with earlier speech perception abilities (p < or = 0.01). CONCLUSIONS The results suggest that speech intelligibility between 2 and 5 yr after implantation in young children with congenital and prelingual profound deafness can be predicted by measures of earlier speech perception.

Approach to communication, speech perception and intelligibility after paediatric cochlear implantation.

Abstract The aim of this study was to explore the relationship between approach to communication, speech perception and speech intelligibility after cochlear implantation of young children with profound early deafness. A prospective speech perception and speech intelligibility assessment was undertaken on a consecutive group of implanted children. There were 46 children at the three-year, 26 at the four-year and 20 at the five-year intervals. All had been born deaf or deafened before the age of three and received cochlear implants before the age of seven. Their speech perception ability and the intelligibility of their speech were measured before cochlear implantation and annually thereafter. The childrens communication had been classified by their teachers of the deaf at each interval into one of two categories: those using an oral approach and those using a signing approach. Results revealed that at all intervals, those children classified as using oral communication significantly exceeded those using signed communication on measures of speech perception and intelligibility (p<0.05). When those children who had changed from signed to oral communication were compared at the three-year interval with those who used oral communication throughout, there was no significant difference in their results. However, it remains to be explored whether children use oral communication after cochlear implantation because they are doing well, or whether they do well because they are using oral communication.

Variations in gains in auditory performance from pediatric cochlear implantation.

Objective To investigate variations in gains in auditory performance in children with cochlear implants. Study Design The auditory performance of 98 children was measured with the Category of Auditory Performance survey instrument. All data were collected prospectively. Variables used to explain gain in Category of Auditory Performance were age at implantation, sex, the duration of “untreated” deafness, the year in which implantation occurred, health care inputs, and cause of hearing impairment. The data were analyzed by ordered probabilistic regression analysis. Results Gain in Category of Auditory Performance was observed to be negatively related to age at implantation, the year in which implantation took place, and the number of medical consultations the child received. None of the other variables were significant determinants of gain in Category of Auditory Performance. Conclusion This study demonstrates the value of examining incremental gain from implantation rather than simply examining outcome levels. It was found that pediatric implantation is subject to diminishing returns. This suggests that further relaxation of entry criteria to implant programs should be undertaken only after careful consideration. The study also confirmed that age at implantation is an important determinant of outcomes. Greater gain in Category of Auditory Performance was experienced by those who underwent implantation at a younger age. This finding has implications for screening, as well as for purchasers and providers of implant services, highlighting the importance of responding in a timely fashion to identified need.

Speech production in deaf implanted children with additional disabilities and comparison with age-equivalent implanted children without such disorders

OBJECTIVE To assess the long-term speech intelligibility in implanted children with additional disorders and compare them with age-equivalent implanted children without such disorders. PATIENTS 175 profoundly deaf children 5 years following cochlear implantation; 67 children with additional difficulties and 108 children without such difficulties. All children were implanted under 5-year-old. MAIN OUTCOME MEASURE Speech intelligibility rating (SIR) scale that can be readily applied to young deaf children irrespective of their performance and is reliable between observers. RESULTS Five years following implantation, 47 (70%) children with additional difficulties developed connected intelligible speech versus 104 (96%) in the control group. However, the quality of speech was quite different between the two groups, as only 11 (16%) children with additional difficulties achieved the two higher categories (intelligible to all or to people with little experience), whereas 66 (61%) children in the control group did (P<0.000001). The total number of additional disorders had the strongest correlation with the outcome. Language and communication disorders were the most important contributing factor, followed by physical, cognitive, and autistic spectrum disorders. CONCLUSION The majority of deaf children with additional disorders develop connected intelligible speech 5 years following implantation; however, a significant proportion do not develop any speech at all. Thus a third of this group did not realise one of the most important objectives for parents of implantation. Benefit from implantation should not be restricted to speech production alone in this specific population.

Does cause of deafness influence outcome after cochlear implantation in children

OBJECTIVES. The objective of this study was to evaluate long-term speech perception abilities of comparable groups of postmeningitic and congenitally deaf children after cochlear implantation. METHODS. This prospective longitudinal study comprised 46 postmeningitic deaf children and 83 congenitally deaf children with age at implantation of ≤5.6 years. Both groups were comparable with respect to educational setting and mode of communication and included children with additional disabilities. RESULTS. Both postmeningitic and congenitally deaf children showed significant progress after implantation. Most (73% and 77%, respectively) could understand conversation without lip-reading or use the telephone with a known speaker 5 years after implantation, whereas none could do so before implantation. At the same interval, the postmeningitic and congenitally deaf children scored a mean open-set speech perception score of 47 (range: 0–91) and 46 (range: 0–107) words per minute, respectively, on connected discourse tracking. The respective mean scores at the 3-year interval were 22 and 29 correct words per minute, respectively. None of these children could score a single correct word per minute before implantation. The progress in both groups was statistically significant. When the 2 groups were compared, there was no statistically significant difference. CONCLUSION. Postmeningitic and congenitally deaf children showed significant improvement in their auditory receptive abilities at the 3- and 5-year intervals after cochlear implantation. There was no statistically significant difference between the outcomes of the 2 groups, suggesting that, provided that children receive an implant early, cause of deafness has little influence on outcome. Although the prevalence of other disabilities was similar in both groups, for individual children, their presence may have profound impact. The study supports the concept of implantation early in life, irrespective of the cause of deafness.

Children's communication mode five years after cochlear implantation: changes over time according to age at implant

One hundred and seventy six children who had received cochlear implants at one centre in the UK were followed up for five years post-implant. The cohort was divided into three groups by age at implant. 1: Under three years of age; 2: Between three and five; 3: Over five. Their mode of communication was noted at four key intervals – pre-implant; 1, 3 and 5 years post-implant. It was classified as either oral or sign. By five years post-implant, 83% of group 1 were using oral communication, 63.5% of group 2 and 45.1% of group 3. The results showed that the mode of communication five years post-implant is statistically related to age at implantation with more children implanted younger using an oral mode of communication (p = 0.001). Children implanted younger are more likely to change communication mode over time from sign to oral, and do so more quickly than those implanted later. Copyright