Hearing preservation in paediatric cochlear implantation with the Nucleus Slim Straight Electrode - our experience.

OBJECTIVE: to evaluate the levels of successful hearing preservation and preservation of functional hearing following cochlear implantation (HPCI) in children using the Cochlear Nucleus® Slim Straight Electrode (SSE). DESIGN: retrospective case note review of paediatric HPCI cases in our CI centre from 2013 to 2023. Inclusion criteria were attempted hearing preservation surgery, SSE used for implantation, pre-operative hearing thresholds ≤80dBHL at 250 Hz, CI before 18 years of age. Patients were excluded if no postoperative unaided PTA was obtained (poor attendance). Primairy outcome was hearing preservation using the HEARRING group formula; secondary outcome was residual functional hearing (≤80dBHL at 250 Hz/<90dB LFPTA). STUDY SAMPLE: 56 patients with 94 CI's were included for review. RESULTS: Hearing preservation was achieved in 94.7% (89/94) of ears and complete preservation in 72% (68/94)). Average functional hearing was preserved in 89% using both criteria for preservation. Long-term follow up data was available for 36 ears (average 35.2 months), demonstrating 88.9% (32/36) complete preservation. CONCLUSION: We have reliably achieved and maintained a high success rate of HPCI using the SSE in our paediatric population. The field of HPCI would benefit from unification of outcome reporting in order to optimise the evidence available to professionals, patients and their carers.

Effect of input compression and input frequency response on music perception in cochlear implant users.

OBJECTIVE: A study was conducted to determine whether modifications to input compression and input frequency response characteristics can improve music-listening satisfaction in cochlear implant users. DESIGN: Experiment 1 compared three pre-processed versions of music and speech stimuli in a laboratory setting: original, compressed, and flattened frequency response. Music excerpts comprised three music genres (classical, country, and jazz), and a running speech excerpt was compared. Experiment 2 implemented a flattened input frequency response in the speech processor program. In a take-home trial, participants compared unaltered and flattened frequency responses. STUDY SAMPLE: Ten and twelve adult Nucleus Freedom cochlear implant users participated in Experiments 1 and 2, respectively. RESULTS: Experiment 1 revealed a significant preference for music stimuli with a flattened frequency response compared to both original and compressed stimuli, whereas there was a significant preference for the original (rising) frequency response for speech stimuli. Experiment 2 revealed no significant mean preference for the flattened frequency response, with 9 of 11 subjects preferring the rising frequency response. CONCLUSIONS: Input compression did not alter music enjoyment. Comparison of the two experiments indicated that individual frequency response preferences may depend on the genre or familiarity, and particularly whether the music contained lyrics.

Cochlear implantation in adolescents: Factors influencing compliance.

OBJECTIVES: To quantify rates of non- and partial-use of cochlear implants (CIs) in adolescent patients implanted in adolescence and childhood and identify factors influencing compliance. METHODS: A retrospective case note review undertaken at The Manchester Auditory Implant Centre. Adolescents were defined as young people aged 11-18 years. Individuals implanted in adolescence were defined as Group 1, individuals implanted in childhood under the age of 3 years and currently adolescents were defined as Group 2 and individuals implanted between the age of 3 and11 years and currently adolescents were defined as Group 3. Non-use was defined as not using the CI at all and partial use was defined as consistently using the CI less than full-time, or fluctuating periods of full and less than full-time use. RESULTS: In Group 1 there was 1 non-user (1.3%) and 11 partial-users (13.9%), with an overall non-compliance rate of 15.2%. In Group 2 there was one non-user (1.9%) and one partial-user (1.9%) with an overall non-compliance rate of 3.8%. In Group 3 there were no non-users and eight partial-users (9%), with an overall non-compliance rate of 9%. The factors influencing compliance differed between groups with the most common factor in Group 1 being a preference for the auditory input gained from the contralateral hearing aid (50%). In Groups 2 and 3 the main factors influencing compliance were behavioural and related to wearing the implant only at school (50 and 75%, respectively). CONCLUSIONS: Patients implanted during adolescence have higher rates of non- and partial-use compared with their adolescent counterparts who have been implanted during childhood. It is important to investigate factors influencing non-compliance so appropriate support may be provided to the patient and their family.

Hearing preservation cochlear implantation in adolescents.

OBJECTIVE: This study describes our experience of cochlear implantation (CI) with hearing preservation in adolescents. Our aim was to determine if hearing preservation is successful in this population, if the preserved hearing is maintained, and what the potential benefit of preserving hearing in this population is. PATIENTS: Fourteen profoundly deaf adolescents with preservation of low-frequency hearing (125, 250, and 500 Hz). INTERVENTION: Twelve adolescents had a single-sided CI, and two had bilateral CI. All were having their first implantation, and all patients had hearing preservation surgery (soft surgery). MAIN OUTCOME MEASURES: Hearing preservation was measured with preoperative and postoperative pure-tone audiograms. Speech audiometry was performed before implantation and at subsequent follow-up appointments. RESULTS: Hearing preservation (measurable hearing thresholds) was achieved in 13 of 14 patients. Average follow-up was 2 years 10 months (range, 4 mo-4 yr 9 mo). Three of 13 patients with initial successful hearing preservation had deterioration of their hearing at subsequent follow-up. The addition of naturally preserved hearing to the cochlear implant improved speech audiometry scores compared with using the implants in isolation. CONCLUSION: This study demonstrates that residual hearing can be consistently preserved and maintained in adolescents during the short-/medium-term using a soft surgical technique to insert standard-length electrodes. The potential benefit of preserving residual low-frequency hearing seems to be improvement in speech discrimination in challenging hearing conditions, although larger studies are required.

Hearing preservation after cochlear reimplantation.

OBJECTIVE: The combination of electrical and acoustical hearing (EAS) is the aim of successful hearing preservation in patients with low-frequency residual hearing who receive a cochlear implant. With adequate surgical treatment and electrode arrays designed for hearing preservation, partial hearing preservation can nowadays be achieved in the majority of patients. Over recent years, the number of patients with EAS has increased, and device failures within this group are a problem that will need to be addressed. It remains unclear how reliably hearing can be preserved during revision surgery. The outcome of 3 subjects requiring cochlear reimplantation after surgery for hearing preservation is presented and discussed. Our aim was to investigate the influence of electrode reinsertion on hearing preservation. PATIENTS: Three patients with measurable residual hearing were implanted with a flexible, free-fitting electrode array in 3 different centers. INTERVENTIONS: Two subjects received a 31.5-mm array inserted 24 mm into the cochlea, whereas a third was treated with a 24-mm array, which was inserted 21 mm into the cochlea. In all cases, hearing was preserved at the initial operation. All of these subjects subsequently represented with device problems, and reimplantation was performed. MAIN OUTCOME MEASURES: Hearing preservation was measured using preoperative and postoperative pure tone audiograms. In addition, speech perception with the implant was evaluated before and after reimplantation surgery. RESULTS: Reimplantation was feasible in all subjects also in cases where a slightly deeper reinsertion was performed. Speech understanding scores after reimplantation were comparable to those seen after the first intervention. CONCLUSION: Revision surgery in patients with preserved hearing after cochlear implantation does not necessarily lead to loss of natural residual hearing, and patients can continue to benefit from the combination of electric and acoustic hearing. Even deeper insertion is possible without hearing loss within residual frequencies.