Biomedical subjects
Publications and source records attributed to D J Mecklenburg.
Although much has been learned in the 5 yr since the first child received a multichannel cochlear implant, we remain at the very early stages of this endeavor. The current evaluation procedures and performance data detailed in subsequent chapters represent the continuation of the efforts described above.
Implants in children of the Nucleus 22-channel system have recently been approved in the United States by the Food and Drug Administration (FDA). Several questions still remains, however, concerning patient selection. This paper presents a statistical method of reporting results and its application to two populations of cochlear implant candidates: congenitally deaf children, and profoundly deaf children with meningitis as the cause of their deafness. It has been suggested that as these two groups may have significantly lower performance than other populations, it may not be appropriate to select them as implant candidates. The statistical method used aggregated single-subject, repeated measures data to reach conclusions on performance. Findings for congenitally deaf subjects evidenced significant improvements over preoperative performance. Results for post-meningitic children showed no significant difference in overall performance compared to non-meningitic children.
Results from 80 pediatric subjects with 12 months of experience wearing the Nucleus multichannel cochlear implant are presented. The data suggest that children demonstrate statistically and clinically significant benefit across a broad spectrum of abilities with the implant. Significant postoperative improvement was demonstrated by 66 percent (51 of 77), 63 percent (45 of 72), and 46 percent (27 of 59) of subjects tested on suprasegmental (prosodic), closed-set and open-set tests, respectively. Forty-nine percent of subjects tested improved when lipreading was combined with sound from the implant, compared with lipreading alone. Children who were deaf at an early age or who had longer duration deafness tended to demonstrate poorer performance on the more difficult perceptual tasks after 12 months of implant experience. However, preliminary evidence suggests that continued improvements by congenital and prelinguistic subjects over longer periods of time may reduce performance differences between subjects with early and later onset deafness.
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The Nucleus 22 Channel cochlear prosthesis developed by the University of Melbourne and Cochlear Pty Ltd is now being used in over 90 clinics worldwide, in fourteen countries and fifteen languages. A total of thirty adolescents and thirty-nine children have now been implanted in Australia, America and more recently Germany. There have been no significant postoperative complications, and the device has been successfully programmed in children as young as two years nine months. Comprehensive evaluation and training programs are being undertaken with each implanted child to assess long term development of speech perception and communication skills. The average postoperative stimulation time for most of the children implanted is around 3 months, so as yet, little data has been recorded on these patients. However, the two original children implanted in Melbourne have now been using their speech processors in excess of 18 months. The focus of this paper will be on the performance of these two children.
The preliminary results from this study indicate that some prelingually deaf patients may get worthwhile help from a multiple-electrode cochlear implant that uses a formant-based speech processing strategy. It is encouraging that these improvements can occur in young adults and teenagers. The results for two children are also encouraging. A 10-year-old child obtained significant improvement on some speech perception tests. It was easy to set thresholds and comfortable listening levels on a 5-year-old child, and he is now a regular user of the device. There are, however, considerable variations in performance among the prelingual patients, which may be related to the following factors: whether they have had some hearing after birth, the method of education used, the motivation of the patient, and age at implantation.
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Explore the source record for details and available documents.
Two programs have been developed for the selection and rehabilitation of children to receive the Nucleus 22-channel cochlear implant system. One program focuses on postlingually deafened children from the ages of 10 to 17, while the other is designed for deafened children from 2 to 9 years. Each has been approved under separate IDEs by the Food and Drug Administration. The selection criteria for these two programs are described. Preliminary results for two adolescents implanted with the Nucleus multichannel device are also presented. Complete pre- and postevaluation results are shown for one adolescent who has completed a ten-week rehabilitation program. Initial findings suggest that hearing-only skills can be developed in this population and that children with short-term deafness may be able to develop some degree of open-set speech recognition without lipreading.
We collected data on 40 patients who received the Nucleus multichannel cochlear implant. Results were reviewed to determine if the coding strategy is effective in transmitting the intended speech features and to assess patient benefit in terms of communication skills. All patients demonstrated significant improvement over preoperative results with a hearing aid for both lipreading enhancement and speech recognition without lipreading. Of the patients, 50% demonstrated ability to understand connected discourse with auditory input only. For the 23 patients who were tested 12 months postoperatively, there was substantial improvement in open-set speech recognition.
A carefully designed study was undertaken in 1982 to evaluate the performance of individuals who received the Nucleus 22-channel cochlear implant. All patients were profound-totally deaf, adults with a postlingual onset of impairment. The preoperative evaluation, prosthesis fitting, training, and postoperative testing were consistent across clinics. Single-subject studies, where each patient acted as his/her own control, revealed that of the 37 subjects, 16-24 obtained significant improvement (P less than or equal to 0.001) on unpracticed, unfamiliar recorded speech tests from the Minimal Auditory Capabilities (MAC) Battery, when using hearing alone (no lipreading). In addition, virtually all patients showed improvement in recognition of speech material with lipreading. The data support the efficacy of a feature extraction coding system where specific formant and amplitude information are transmitted via direct electrical stimulation to the cochlea.