A longitudinal study of the bilateral benefit in children with bilateral cochlear implants.

OBJECTIVE: To study the development of the bilateral benefit in children using bilateral cochlear implants by measurements of speech recognition and sound localization. DESIGN: Bilateral and unilateral speech recognition in quiet, in multi-source noise, and horizontal sound localization was measured at three occasions during a two-year period, without controlling for age or implant experience. Longitudinal and cross-sectional analyses were performed. Results were compared to cross-sectional data from children with normal hearing. STUDY SAMPLE: Seventy-eight children aged 5.1-11.9 years, with a mean bilateral cochlear implant experience of 3.3 years and a mean age of 7.8 years, at inclusion in the study. Thirty children with normal hearing aged 4.8-9.0 years provided normative data. RESULTS: For children with cochlear implants, bilateral and unilateral speech recognition in quiet was comparable whereas a bilateral benefit for speech recognition in noise and sound localization was found at all three test occasions. Absolute performance was lower than in children with normal hearing. Early bilateral implantation facilitated sound localization. CONCLUSIONS: A bilateral benefit for speech recognition in noise and sound localization continues to exist over time for children with bilateral cochlear implants, but no relative improvement is found after three years of bilateral cochlear implant experience.

Bilateral versus unilateral cochlear implants in children: speech recognition, sound localization, and parental reports.

OBJECTIVE: To compare bilateral and unilateral speech recognition in quiet and in multi-source noise, and horizontal sound localization of low and high frequency sounds in children with bilateral cochlear implants. DESIGN: Bilateral performance was compared to performance of the implanted side with the best monaural speech recognition in quiet result. Parental reports were collected in a questionnaire. Results from the CI children were compared to binaural and monaural performance of normal-hearing peers. STUDY SAMPLE: Sixty-four children aged 5.1-11.9 years who were daily users of bilateral cochlear implants. Thirty normal-hearing children aged 4.8-9.0 years were recruited as controls. RESULTS AND CONCLUSIONS: Group data showed a statistically significant bilateral speech recognition and sound localization benefit, both behaviorally and in parental reports. The bilateral speech recognition benefit was smaller in quiet than in noise. The majority of subjects localized high and low frequency sounds significantly better than chance using bilateral implants, while localization accuracy was close to chance using unilateral implants. Binaural normal-hearing performance was better than bilateral performance in implanted children across tests, while bilaterally implanted children showed better localization than normal-hearing children under acute monaural conditions.

The Intra-Cochlear Impedance-Matrix (IIM) test for the Nucleus® cochlear implant.

OBJECTIVE: To describe the principles and operation of a new telemetry-based function test for the Nucleus® cochlear implant, known as the CS19 Intra-Cochlear Impedance Matrix (IIM) and to present results from a multicentre clinical study to establish reproducibility (test-retest reliability) and normative ranges. METHOD: The IIM test measures bipolar impedances between all electrode pairs and employs a normalization procedure based on common ground impedances in order to identify abnormal current paths among electrodes. Six European clinics collected IIM data from a total of 192 devices. RESULTS: Reproducibility was high between initial and repeat measurements. The normative analysis demonstrated narrow ranges among devices after normalization of impedance data. The IIM is able to identify abnormal current paths that are not evident from standard impedance telemetry and may otherwise only be found utilising average electrode voltage measurements (AEV). CONCLUSIONS: The IIM test was found to be straightforward to perform clinically and demonstrated reproducible data with narrow ranges in normally-functioning devices. Because this test uses a very low stimulation level the IIM test is well suited for children or multiply handicapped CI users who cannot reliably report on their auditory percepts. The new algorithms show potential to improve implant integrity testing capabilities if implemented in future clinical software.

Remote programming of MED-EL cochlear implants: users' and professionals' evaluation of the remote programming experience.

CONCLUSION: Remote programming is safe and is well received by health-care professionals and cochlear implant (CI) users. It can be adopted into clinic routine as an alternative to face-to-face programming. OBJECTIVES: Telemedicine allows a patient to be treated anywhere in the world. Although it is a growing field, little research has been published on its application to CI programming. We examined hearing professionals' and CI users' subjective reactions to the remote programming experience, including the quality of the programming and the use of the relevant technology. METHODS: Remote CI programming was performed in Italy, Sweden, and Russia. Programming sessions had three participants: a CI user, a local host, and a remote expert. After the session, each CI user, local host, and remote expert each completed a questionnaire on their experience. RESULTS: In all, 33 remote programming sessions were carried out, resulting in 99 completed questionnaires. The overwhelming majority of study participants responded positively to all aspects of remote programming. CI users were satisfied with the results in 96.9% of the programming sessions; 100% of participants would use remote programming again. Although technical problems were encountered, they did not cause the sessions to be considerably longer than face-to-face sessions.

Horizontal sound localization in children with bilateral cochlear implants: effects of auditory experience and age at implantation.

OBJECTIVE: To study sound localization performance in relation to auditory experience and age at implantation in children with bilateral cochlear implants. STUDY DESIGN: Clinical study. SETTING: University hospital. PATIENTS: Sixty-two sequentially and 4 simultaneously bilaterally implanted children participated in this clinical sound localization study, at a median age of 5.6 years. They underwent sequential implantations at median ages of 1.9 and 4.2 years, respectively. Simultaneous implantations were performed at a median age of 2.0 years. METHODS: Localization performance was measured with pink noise presented in random order from 5 loudspeakers in the frontal horizontal plane. Twenty-one subjects participated in repeated testing. MAIN OUTCOME MEASURE: Sound localization performance as quantified with an Error Index. RESULTS: On group level, bilaterally implanted children pinpointed the sounding loudspeaker in the frontal horizontal plane. Sound localization performance improved significantly with increasing bilateral cochlear implant experience, as observed in the entire study group and intraindividually, albeit large interindividual variability existed. Regression analyses in the entire study group and in the sequentially implanted children did not reveal any relationship between sound localization performance and ages at first and second implantation, interimplant interval, or age. However, second implantation before 4 years of age contributed to faster sound localization improvement with increasing bilateral cochlear implant experience. CONCLUSION: Median perceived azimuths coincided with presented azimuths. We suggest that listening experience after bilateral cochlear implantation affects sound localization performance, possibly owing to the ongoing stimulus-driven maturation of the central auditory system. The amount of time listening with bilateral implants has methodologic implications on sound localization assessment in bilaterally implanted children.