Perspectives on Support Material for Referrals to Cochlear Implantation Teams.

PURPOSE: This study used a collaborative approach to explore the needs, barriers, and facilitators to developing cochlear implant referral information material that would be valuable for hard of hearing adults and referring audiologists. METHOD: During the development of a prototype referral aid to be used within the Australian context, a multistage qualitative study was conducted using a consultative process, informal and semistructured interviews, as well as online surveys. A deductive directed content analysis approach was applied to assess respondents' perspectives. A total of 106 participants (37 hard of hearing adults and 69 audiologists) were involved across the multiple phases of this study. RESULTS: Referral practices for the evaluation of cochlear implantation candidacy in Australia are highly inconsistent, supporting the need to streamline referral information. The following facilitators were identified to support the development of referral material: appropriate content, perceived patient benefit, and objectivity. Areas for improvement related to the broadness of the content, impact on professional identity, and accessibility. CONCLUSIONS: Practical insight from patients and referrers can inform the development of patient-facing material related to cochlear implant referrals. Streamlining information used in educational material could alleviate confusion inherent to varied health literacy levels and support patients in making informed decisions related to pursuing, or not, cochlear implantation candidacy evaluation services.

Relationship Between Objective and Behavioral Audiology for Young Children Being Assessed for Cochlear Implantation: Implications for CI Candidacy Assessment.

OBJECTIVE: This study aimed to evaluate the feasibility of making cochlear implant recommendations based on diagnostic ABR and ASSR results. The goal was to challenge the need for behavioral audiometry as part of the standard cochlear implant assessment battery for infants with profound hearing loss and to reduce the age at which cochlear implant recommendation was made. STUDY DESIGN: A retrospective review of 123 patient files for children referred to the pediatric cochlear implant service before 3 years of age over a 3-year period was undertaken. Results for click-ABR, ASSR, and behavioral audiology at 500, 1k, 2k and 4k Hz, and tympanometry were collected and relationships were investigated for 64 children who met the inclusion criteria. Data were excluded for 59 children due to the presence of auditory neuropathy findings, middle ear pathology at the time of testing, if ASSR was not assessed at intensity levels >85 dB, and/or behavioral testing was judged to be unreliable by two experienced clinicians. SETTING: Primary care pediatric cochlear implant program located within a hospital setting. PATIENTS: Pediatric patients referred for cochlear implant evaluation before 3 years of age. INTERVENTIONS(S): Children were assessed using ABR, ASSR, and behavioral audiometry for identification and confirmation of hearing loss. MAIN OUTCOME MEASURES(S): Correlation between diagnostic click-ABR and ASSR thresholds and subsequently obtained behavioral hearing thresholds. RESULTS: Results for objective measures (click-ABR and ASSR) were significantly correlated with behavioral results. The correlations, however, were poorer than expected with limited predictive value. For 6 of the 64 children click-ABR and/or ASSR suggested profound hearing loss and corresponding behavioral hearing threshold was found to be in the severe hearing loss range. CONCLUSIONS: Findings of this study do not support making cochlear implant recommendations based on the findings of diagnostic click-ABR and ASSR alone. Investigating ways to reduce the average age children with severe-to-profound hearing loss receive a cochlear implant is a priority for the study institution. An alternate evaluation pathway for infants which incorporates a multifaceted assessment is warranted and will be the focus of future work at the study institution.

Receptive language as a predictor of cochlear implant outcome for prelingually deaf adults.

OBJECTIVE: This study investigated outcomes and predictive factors, specifically language skills, for a group of prelingually hearing-impaired adults who received a cochlear implant. DESIGN: Speech perception data, demographic information, and other related variables such as communication mode, residual hearing, and receptive language abilities were explored. Pre- and post-implant speech perception scores were compared and multiple regression analysis was used to identify significant predictive relationships. STUDY SAMPLE: The study included 43 adults with a prelingual onset of hearing loss, who proceeded with cochlear implantation at the Royal Victorian Eye and Ear Hospital in Melbourne, Australia. RESULTS: The majority of patients experienced benefit from their cochlear implants, with 88% demonstrating significant improvement in speech perception performance. Volunteers achieved better post-operative speech perception scores if they had a shorter duration of severe-to-profound hearing loss, better language skills, and used an exclusively oral communication mode. CONCLUSIONS: Although post-operative speech perception performance is significantly poorer for prelingually hearing-impaired adults compared to postlingually hearing-impaired patients, the study group demonstrated significant benefit from their cochlear implants. The variability in post-operative outcomes can be predicted to some extent from the hearing history and language abilities of the individual patient.

Evidence-based guidelines for recommending cochlear implantation for young children: Audiological criteria and optimizing age at implantation.

OBJECTIVE: Establish up-to-date evidence-based guidelines for recommending cochlear implantation for young children. DESIGN: Speech perception results for early-implanted children were compared to children using traditional amplification. Equivalent pure-tone average (PTA) hearing loss for cochlear implant (CI) users was established. Language of early-implanted children was assessed over six years and compared to hearing peers. STUDY SAMPLE: Seventy-eight children using CIs and 62 children using traditional amplification with hearing losses ranging 25-120 dB HL PTA (speech perception study). Thirty-two children who received a CI before 2.5 years of age (language study). RESULTS: Speech perception outcomes suggested that children with a PTA greater than 60 dB HL have a 75% chance of benefit over traditional amplification. More conservative criteria applied to the data suggested that children with PTA greater than 82 dB HL have a 95% chance of benefit. Children implanted under 2.5 years with no significant cognitive deficits made normal language progress but retained a delay approximately equal to their age at implantation. CONCLUSIONS: Hearing-impaired children under three years of age may benefit from cochlear implantation if their PTA exceeds 60 dB HL bilaterally. Implantation as young as possible should minimize any language delay resulting from an initial period of auditory deprivation.

A multicentre clinical evaluation of paediatric cochlear implant users upgrading to the Nucleus(®) 6 system.

OBJECTIVES: The aim of this study was to investigate whether experienced paediatric cochlear implant users could show benefits to speech perception outcomes from the introduction of noise reduction and automated scene classification technologies as implemented in the Nucleus(®) 6 sound processor. Previous research with adult cochlear implant users had shown significant improvements in speech intelligibility for listening in noisy conditions and good user acceptance for upgrading to the Nucleus 6 processor. In adults, these improvements for listening in noise were primarily attributed to the use of a range of new input processing technologies including noise reduction, as well as introduction of automatic scene classification technology. METHODS: Experienced paediatric cochlear implant users (n=25) were recruited from four clinics located in three countries. Research participants were evaluated on three occasions, an initial session using their Nucleus 5 sound processor; a second session in which participants used the Nucleus 6 processor programmed with the same technologies as were used in their Nucleus 5 sound processor; and a final session in which participants used the Nucleus 6 processor programmed with the default technologies including automatic scene classification (SCAN) which automatically selects the microphone directionality, noise reduction (SNR-NR), and wind noise reduction (WNR) technologies. Prior to both the second and third evaluations, research participants had approximately two weeks take-home experience with the new system. Speech perception performances on monosyllabic word tests presented in quiet and in noise, and a sentence test presented in noise, were compared across the three processor conditions. Acceptance of the Nucleus 6 default settings was assessed in a final session. RESULTS: No group mean difference in performance was found for monosyllabic words in quiet. A significant improvement in speech perception was found for both monosyllabic words and sentences in noise with the default Nucleus 6 program condition as compared with the Nucleus 5 condition. No acceptance issues were noted for any of the children. CONCLUSIONS: Experienced paediatric cochlear implant users showed a significant improvement in speech perception in listening in noise when upgraded to the Nucleus 6 sound processor primarily due to the introduction of a noise reduction technology, and all children accepted the default program. These findings suggest that school-aged children may benefit from upgrading to the Nucleus 6 sound processor using the default program.

Evidence-based guidelines for recommending cochlear implantation for postlingually deafened adults.

OBJECTIVE: Adult selection criteria for cochlear implantation have been developed based on analysis of the post-operative performance of a large group of postlingually deafened adults. Original criteria published in 2004 were reviewed and amended to reflect outcomes currently being achieved by implant recipients. DESIGN: Retrospective review of 12-month post-operative speech perception performance of adults implanted at the Eye and Ear Hospital, Melbourne, Australia. STUDY SAMPLE: A total of 382 postlingually deafened adults, using a Freedom, Nucleus 5, or CI422 Slim Straight cochlear implant were used to create a comparative set of data. RESULTS: Revised guidelines suggest that adults with postlingual hearing loss can now be considered cochlear implant candidates if they obtain scores of up to 55% for open-set phonemes in quiet in the ear to be implanted. Functional benefit may vary depending on the recipients' contralateral hearing. CONCLUSIONS: This study supports the provision of cochlear implants to candidates with significant residual hearing when at least one ear meets the criterion outlined above. Patient-specific counseling is required to ensure the potential to benefit predicted by the current model is acceptable to the individual patient and their family. Counseling regarding functional benefit must take into consideration hearing in the contralateral ear.

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 χ2 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.

Usefulness of MRI and EABR Testing for Predicting CI Outcomes Immediately After Cochlear Implantation in Cases With Cochlear Nerve Deficiency.

OBJECTIVE: Cochlear nerve deficiency (CND) is often associated with poor cochlear implant (CI) outcomes, and patients with CND may be candidates for auditory brainstem implantation (ABI). The purpose of this study was to identify investigations which predict CI outcomes immediately after cochlear implantation to recommend ABI within the critical period of auditory development when cochlear implantation precedes ABI. STUDY DESIGN: Retrospective case review. SETTING: Cochlear implant centers at tertiary referral hospitals. PATIENTS: Nineteen children with CND who underwent cochlear implantation and intraoperative electrically evoked auditory brainstem response (EABR) testing. INTERVENTIONS: Diagnostic and therapeutic. MAIN OUTCOME MEASURES: Preoperative MRI and intraoperative EABR were used to evaluate relative diameter of the vestibulocochlear nerve (CN8) compared to the facial nerve (CN7) at the cerebellopontine angle and presence of evoked wave Vs (eVs) with typical latency, respectively. Correlation between 2-year postoperative categories of auditory performance (CAP) scores and results of MRI and EABR were evaluated. RESULTS: Each classification using MRI or EABR was significantly associated with the CI outcomes. Combination of the MRI and EABR results allowed better discrimination between poor CI users and moderate to good CI users than either examination used separately. All children in "CN7 > CN8/negative eV" showed ≤3, while all in "CN7 ≤ CN8/positive eV" achieved ≥3 in the postoperative CAP score. CONCLUSIONS: Combination of MRI and EABR results allows prediction of CI outcomes immediately after cochlear implantation. This should facilitate management decision making for auditory implantation in children with CND.

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.

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.

How we do it: clinical management of the child receiving a second, bilateral cochlear implant.

For children to gain maximum benefit from a second, bilateral cochlear implant clinicians need to be aware of the special needs of the family and child, and to adapt their clinical management appropriately. This article describes how the situation of the family considering a second implant is different, and how the decision to be made differs from that for a first implant. The information specific to sequential implants that should be provided so families can make an informed decision is reviewed. Programming issues unique to sequential bilateral cochlear implants are discussed. Finally, information is provided on how children may respond post-operatively, and what can be done to promote bilateral device use and the development of listening skills with the new implant.

Communication development in children who receive the cochlear implant younger than 12 months: risks versus benefits.

BACKGROUND: The advent of universal neonatal hearing screening in some countries and the availability of screening programs for at-risk infants in other countries has facilitated earlier referral, diagnosis, and intervention for infants with hearing loss. Improvements in device technology, two decades of pediatric clinical experience, a growing recognition of the efficacy of cochlear implants for young children, and the recent change in the U.S. Food and Drug Administration's age criteria to include children as young as 12 mo has led to increasing numbers of young children receiving cochlear implants. Evidence to support provision for infants younger than 12 mo is extrapolated from physiological studies, studies of children using hearing aids, and studies of children older than 12 mo of age with implants. To date, however, there are few published research findings regarding communication development in children between 6 and 12 mo of age who receive implants. The current study hypothesized that earlier implantation would lead to increased rates of language acquisition as the children were still in the critical period for their development. METHOD: A retrospective review was completed for 19 infants (mean age at implantation, 0.88 yr; range, 0.61-1.07, SD 0.15) and 87 toddlers (mean age at implantation, 1.60 yr; range, 1.13-2.00, SD 0.24) who received the multichannel implant in Melbourne, Australia. Preimplantation audiological assessments for these children included aided and unaided audiograms, auditory brain stem response, auditory steady state response (ASSR), and otoacoustic emission and indicated profound to total bilateral hearing loss in all cases. Communication assessment included completion of the Rossetti Infant-Toddler Language Scale and educational psychologists' cognitive and motor assessment. Computed tomography scan, magnetic resonance imaging, and surgical records for all cases were reviewed. Postimplantation language assessments were reported in terms of the rate of growth over time on the language comprehension and language expression subscales of the Rossetti Infant-Toddler Language Scale. RESULTS: Results demonstrated that cochlear implantation may be performed safely in very young children with excellent language outcomes. The mean rates of receptive (1.12) and expressive (1.01) language growth for children receiving implants before the age of 12 mo were significantly greater than the rates achieved by children receiving implants between 12 and 24 mo, and matched growth rates achieved by normally hearing peers. These preliminary results support the provision of cochlear implants for children younger than 12 mo of age within experienced pediatric implantation centers.

Evaluation of streamlined programming procedures for the Nucleus cochlear implant with the Contour electrode array.

OBJECTIVE: The objective of this study was to evaluate streamlined programming procedures for the Nucleus cochlear implant system with the Contour electrode array. DESIGN: Phase 1 involved an examination of the clinical MAPs for the first 103 recipients implanted with the Contour electrode array in the Melbourne Cochlear Implant Clinic, to examine the ability to predict the entire MAP based on a smaller number of clinically determined T- and/or C-levels. In phase 2, a subset of the streamlined procedures was selected and clinically evaluated, using speech perception and subjective preference measures. In the first study, the clinical MAP was compared with a MAP based on interpolating across three behavioral T-levels and three behavioral C-levels in a group of newly implanted subjects. The second study investigated the use of a single interpolated profile as the basis to creating the entire MAP. Initial evaluation compared the clinical MAP with two streamlined MAPs, one in which the C-level profile was derived from interpolation across a subset of T-levels and one in which the T-level profile was derived from interpolation across a subset of C-levels. In this case, the interpolated profile was based on five behavioral measures. Subsequently, the use of either three or a single T-level measure as the basis for the interpolated T-level profile was evaluated. Eighteen subjects, who were experienced with the clinical MAP before enrollment in the study, participated in the initial evaluation. The subjects were selected to include a group whose RMS deviation from clinical MAP levels, as determined in Phase 1, was greater than that of the wider population. RESULTS: The Phase 1 analysis showed that as expected, larger differences were observed between the clinical and derived MAP levels as interpolation was applied across fewer measured electrodes and that the use of a single interpolated profile to create the entire MAP resulted in the greatest deviation. No significant group mean difference was found in speech perception scores for newly implanted subjects when mapped with the clinical versus the streamlined MAP based on three behavioral T- and three behavioral C-level measures. For some individual subjects, scores were higher with the streamlined MAP. Subjective reports from the comparative performance questionnaire were consistent with these findings. No significant group mean difference in speech perception scores was found in comparing the clinical MAP with the streamlined MAPs based on a single interpolated T- or C-level profile created from five behavioral measures. Individual effects were observed; however, there was no consistent finding across subjects. The use of three rather than five behavioral T-level measures in the procedure did not result in significantly lower group mean scores; however, significantly poorer scores were obtained for three of the 10 individual subjects. The use of a MAP based on a single behavioral measure did result in poorer speech perception scores when compared with the MAP based on five behavioral T-level measures. These findings were consistent with subjective results from the performance questionnaires administered to determine preference for program across a range of listening situations. CONCLUSIONS: Two streamlined programming procedures are recommended for use in the clinical setting: (1) interpolating across three measured T-levels and three measured C-levels and (2) interpolating across five measured T- or C-levels and using the interpolated profile for fitting of the alternative profile.

Optimizing frequency-to-electrode allocation in cochlear implants.

This study tested the hypothesis that speech perception of cochlear implant users could be improved by increasing the number of electrodes allocated to frequencies below 2.6 kHz, with correspondingly fewer electrodes allocated above this point. Eight users of the Nucleus CI22 implant participated and wore experimental maps in which the widths of the analysis filters were altered to provide either two or three extra low-frequency channels. Speech perception was tested following periods of take-home experience. Information transmission analysis of vowel and consonant confusions appear to support our hypothesis, showing that vowel first formant information was significantly better perceived with the experimental map and that consonant information was not significantly different. The results of CNC word testing appear to contradict this result, showing that the experimental map degraded both vowel and consonant perception. Overall, the experimental map had a small and variable effect on speech perception. These results do not support our hypothesis and indicate that further research is needed to investigate the possible effects of narrowing the filter bandwidth in low frequencies, as done in this experiment.