Shani J. Dettman

Communication Development in Children Who Receive a Cochlear Implant by 12 Months of Age

Objective Describe the long-term benefits of early cochlear implantation. Provide a comprehensive description of outcomes, including: language, speech production, and speech perception. Compare the communication outcomes for the early implanted children to those of normally hearing children and children who received a cochlear implant at a comparatively older age. Method Retrospective review of the communication development of 35 children implanted between 6 and 12 months of age and 85 children implanted between 13 and 24 months of age. Audiologic assessments included unaided and aided audiograms, auditory brainstem response (ABR), auditory steady state response (ASSR), and otoacoustic emissons (OAEs). Formal language, speech production, and speech perception measures were administered, preimplant and at 1, 2, 3, and 5 years postimplant. Results The children who received their cochlear implant by 12 months of age demonstrated language growth rates equivalent to their normally hearing peers and achieved age appropriate receptive language scores 3 years postimplant. The children who received their cochlear implant between 13 and 24 months demonstrated a significant language delay at 3 years postimplant. Speech production development followed a similar pattern to that of normal-hearing children, although was delayed, for both groups of children. Mean open-set speech perception scores were comparable with previous reports for children and adults who use cochlear implants. Conclusion Children implanted by 12 months of age demonstrate better language development compared with children who receive their cochlear implant between 13 and 24 months. This supports the provision of a cochlear implant within the first year of life to enhance the likelihood that a child with severe-to-profound hearing impairment will commence elementary school with age-appropriate language skills.

A clinical report on receptive vocabulary skills in cochlear implant users

Objective The aim was to measure the rate of vocabulary acquisition for cochlear implant users and compare the pre- and postoperative rates with published data for other groups with normal or impaired hearing. The hypothesis was that the postoperative rate would be greater than the preoperative rate. Design The Peabody Picture Vocabulary Test (PPVT) was administered to 32 children, adolescents, and prelinguistically deafened adults implanted with the 22-electrode cochlear implant. Age at implantation ranged from 2 yr 6 mo to 20 yr and implant use ranged from 6 mo to 7 yr 8 mo. Results The group mean postoperative performance at various postoperative intervals was significantly higher than mean preoperative performance. Single-subject data indicated statistically significant gains over time on this test for 13 of the subjects. The mean postoperative rate of vocabulary acquisition of 1.06 times the rate for normally hearing children was significantly greater than the mean preoperative rate of 0.43. Conclusions These rates of improvement were in accord with previous reports on smaller numbers of implant users, but could not be attributed unambiguously to use of the implant because no control group was used for this clinical work. Variables such as age at implantation, duration of profound deafness, communication mode, and speech perception skill failed to significantly predict rate of improvement on the PPVT.

Speech perception in children using cochlear implants: prediction of long-term outcomes

Abstract A group of 102 children using the Nucleus multichannel cochlear implant were assessed for open-set speech perception abilities at six-monthly intervals following implant surgery. The group included a wide range of ages, types of hearing loss, ages at onset of hearing loss, experience with implant use and communication modes. Multivariate analysis indicated that a shorter duration of profound hearing loss, later onset of profound hearing loss, exclusively oral/aural communication and greater experience with the implant were associated with better open-set speech perception. Developmental delay was associated with poorer speech perception and the SPEAK signal coding scheme was shown to provide better speech perception performance than previous signal processors. Results indicated that postoperative speech perception outcomes could be predicted with an accuracy that is clinically useful.

A clinical report on speech production of cochlear implant users

Objective The aim was to assess articulation and speech intelligibility over time in a group of cochlear implant users implanted at 8 yr or over. The hypothesis was that the postoperative speech production performance would be greater than the preoperative performance. Design A test of intelligibility using sentences and an articulation test measuring non-imitative elicited speech were administered to 11 and 10 subjects, respectively, who were implanted with the 22-elec-trode cochlear implant. Nine subjects received both tests. Age at implantation ranged from 8 yr to 20 yr and implant use ranged from 1 yr to 4 yr 5 mo. Results For both the intelligibility and articulation tests roughly half of the subjects showed significant improvements over time and group mean postoperative performance significantly exceeded preoperative performance. Improvements occurred for front, middle, and back consonants; for stops, fricatives, and glides and for voiceless and voiced consonants. Conclusions Despite being deprived of acoustic speech information for many childhood years, roughly half of the patients assessed showed significant gains in speech intelligibility and articulation postimplantation. The lack of a control group of non-implanted patients means that we cannot separate out the influence of the implant on speech production from other influences such as training and tactile-kinaesthetic feedback.

Speech perception outcomes in older children who use multichannel cochlear implants: Older is not always poorer

Speech perception outcomes for early-deafened children who undergo implantation as teenagers or young adults are generally reported to be poorer than results for young children. It is important to provide appropriate expectations when counseling adolescents and their families to help them make an informed choice regarding cochlear implant surgery. The considerable variation of results in this group makes this process more difficult. This study considered a number of factors in a group of 25 children who underwent implantation in Melbourne between the ages of 8 and 18 years. Each subject completed open-set speech perception testing with Bamford-Kowal-Bench sentences before and after implantation and preoperative language testing with the Peabody Picture Vocabulary Test. Data were collected regarding the type of hearing loss, age at implantation, age at hearing aid fitting, audiometric details, and preoperative and postoperative communication mode. Results were submitted to a stepwise multiple linear regression analysis with postoperative open-set sentence scores as the dependent variables. The analysis suggested that 3 factors have a significant predictive value for speech perception after implantation: preoperative open-set sentence score, duration of profound hearing loss, and equivalent language age. These 3 factors accounted for 66% of the variance in this group. The results of this study suggest that children who have useful speech perception before implantation, and higher age-equivalent scores on language measures, would be expected to do well with a cochlear implant. Consistent with other studies, a shorter duration of profound hearing loss is also advantageous. The mean sentence score for this group, 47%, was not significantly different from the mean result across all children in the Melbourne program.

Evidence-Based Approach for Making Cochlear Implant Recommendations for Infants With Residual Hearing

Objectives: The aim of this study was to develop guidelines, based on the unaided pure-tone audiogram, for recommending a cochlear implant (CI) for infants and young children with residual hearing. As awareness of the benefits of early implantation increases and age at diagnosis decreases, an increasing number of infants are presenting for consideration of implantation with significant residual hearing in one or both ears. Determining the likelihood that these infants will have an improved speech and language outcome if they receive a CI is a challenge. Design: Subjects were 142 hearing impaired children (ages 4.6 to 16.2 yrs) with unaided three-frequency pure-tone average (PTA; at 500, 1000, and 2000 Hz) ranging from 28 to 125 dB HL: 62 used conventional amplification (analog or digital hearing aids [HAs]) and the remaining 80 used a Nucleus 24 (N24) or Freedom CI. Open-set monosyllabic word (Phonetically Balanced Kindergarten or Consonant-Nucleus-Consonant words) and sentence (Bamford-Kowal-Bench sentences) testing was administered audition alone to both groups of children. Results: Comparison of means for sentence testing showed that the children using CIs performed significantly better than their peers with profound hearing loss (PTA >90 dB HL) using HAs and not significantly differently to those with severe (PTA 66 to 90 dB HL) or moderate (PTA <66 dB HL) hearing loss. Comparison of means for monosyllabic word testing showed that the children using CIs performed significantly better than their peers with severe and profound hearing loss and not significantly differently to those with moderate hearing loss. Regression analysis was used to determine the equivalent unaided PTA values that corresponded to the median and first quartile scores for the children using CIs on speech perception testing. For open-set words, scored for phonemes correct, the equivalent unaided PTAs were 46 and 56 dB HL, respectively. For sentence testing, the equivalent unaided PTAs were 63 and 72 dB HL, respectively. Conclusions: Results suggest that recommendation for implantation can be made confidently for children presenting with bilateral profound hearing loss. For children with unaided PTA hearing levels in the range of 75 to 90 dB HL, a recommendation for implantation can also be made, provided that a 75% chance of improvement in hearing outcome is an acceptable level of benefit to the family and clinician. Children presenting with PTA hearing levels better than 75 dB HL should be encouraged to continue with binaural HA use.

Long-term Communication Outcomes for Children Receiving Cochlear Implants Younger Than 12 Months: A Multicenter Study.

Objective: Examine the influence of age at implant on speech perception, language, and speech production outcomes in a large unselected paediatric cohort. Study Design: This study pools available assessment data (collected prospectively and entered into respective databases from 1990 to 2014) from three Australian centers. Patients: Children (n = 403) with congenital bilateral severe to profound hearing loss who received cochlear implants under 6 years of age (excluding those with acquired onset of profound hearing loss after 12 mo, those with progressive hearing loss and those with mild/moderate/severe additional cognitive delay/disability). Main Outcome Measure(s): Speech perception; open-set words (scored for words and phonemes correct) and sentence understanding at school entry and late primary school time points. Language; PLS and PPVT standard score equivalents at school entry, CELF standard scores. Speech Production; DEAP percentage accuracy of vowels, consonants, phonemes-total and clusters, and percentage word-intelligibility at school entry. Results: Regression analysis indicated a significant effect for age-at-implant for all outcome measures. Cognitive skills also accounted for significant variance in all outcome measures except open-set phoneme scores. ANOVA with Tukey pairwise comparisons examined group differences for children implanted younger than 12 months (Group 1), between 13 and 18 months (Group 2), between 19 and 24 months (Group 3), between 25 and 42 months (Group 4), and between 43 and 72 months (Group 5). Open-set speech perception scores for Groups 1, 2, and 3 were significantly higher than Groups 4 and 5. Language standard scores for Group 1 were significantly higher than Groups 2, 3, 4, and 5. Speech production outcomes for Group 1 were significantly higher than scores obtained for Groups 2, 3, and 4 combined. Cross tabulation and &khgr;2 tests supported the hypothesis that a greater percentage of Group 1 children (than Groups 2, 3, 4, or 5) demonstrated language performance within the normative range by school entry. Conclusions: Results support provision of cochlear implants younger than 12 months of age for children with severe to profound hearing loss to optimize speech perception and subsequent language acquisition and speech production accuracy.

Communication outcomes for groups of children using cochlear implants enrolled in auditory-verbal, aural-oral, and bilingual-bicultural early intervention programs.

Objective The relative impact of early intervention approach on speech perception and language skills was examined in these 3 well-matched groups of children using cochlear implants. Study Design Eight children from an auditory verbal intervention program were identified. From a pediatric database, researchers blind to the outcome data, identified 23 children from auditory oral programs and 8 children from bilingual-bicultural programs with the same inclusion criteria and equivalent demographic factors. Patients All child participants were male, had congenital profound hearing loss (pure tone average >80 dBHL), no additional disabilities, were within the normal IQ range, were monolingual English speakers, had no unusual findings on computed tomography/magnetic resonance imaging, and received hearing aids and cochlear implants at a similar age and before 4 years of age. Main Outcome Measures Open-set speech perception (consonant-nucleus-consonant [CNC] words and Bamford-Kowal-Bench [BKB] sentences) and the Peabody Picture Vocabulary Test (PPVT) were administered. Results The mean age at cochlear implant was 1.7 years (range, 0.8–3.9; SD, 0.7), mean test age was 5.4 years (range, 2.5–10.1; SD, 1.7), and mean device experience was 3.7 years (range, 0.7–7.9; SD, 1.8). Results indicate mean CNC scores of 60%, 43%, and 24% and BKB scores of 77%, 77%, and 56% for the auditory-verbal (AV), aural-oral (AO), and bilingual-bicultural (BB) groups, respectively. The mean PPVT delay was 13, 19, and 26 months for AV, AO, and BB groups, respectively. Conclusion Despite equivalent child demographic characteristics at the outset of this study, by 3 years postimplant, there were significant differences in AV, AO, and BB groups. Results support consistent emphasis on oral/aural input to achieve optimum spoken communication outcomes for children using cochlearimplants.

Cochlear Implants in Forty-Eight Children with Cochlear and/or Vestibular Abnormality

CT and MRI scans for 48 children with cochlear and/or vestibular abnormality were classified in decreasing severity; common cavity, Mondini plus enlarged vestibular aqueduct, Mondini dysplasia alone and enlarged vestibular aqueduct alone. No significant relationship between degree of cochlea abnormality and surgical issues (cerebrospinal fluid gusher, depth of insertion, number of electrodes) or speech perception/language outcomes was found. A significant relationship was observed between cerebrospinal fluid gusher and partial electrode insertion, fewer active electrodes and poorer sentence understanding. Optimum language outcomes were associated with younger age at implant.

Language outcomes for children with cochlear implants enrolled in different communication programs

Abstract Objectives The aims of this study were to (a) compare language outcomes in pediatric cochlear implant users enrolled in three different communication programs: sign and spoken language, auditory–oral, and auditory–verbal therapy, and (b) examine factors influencing language outcomes. Methods Post-implant standard scores on language assessments of receptive vocabulary, auditory comprehension, and expressive communication were collected from files of 42 children with prelingual hearing loss who were implanted by 3;6 years of age. Early intervention history, device details, and demographic information were obtained for each child. Family involvement was evaluated using a rating scale. Results After adjusting for potential covariates, there were no significant differences in language outcomes across the three groups. Overall, there was a large degree of variability with some children achieving below average scores and others achieving above average scores. Age at diagnosis of hearing loss and family involvement were significantly associated with language outcomes. Conclusion Regardless of the type of communication approach received, children diagnosed with hearing loss at an early age and children with a high level of family involvement had better post-implant language scores than children diagnosed later and with lower levels of family involvement. These findings emphasize the importance of early diagnosis and highlight the contribution families make to the language outcomes of children with cochlear implants.