Susan Zimmerman-Phillips

Independent evaluation of the speech perception abilities of children with the nucleus 22-channel cochlear implant system

The performance of 28 children with the Nucleus multichannel cochlear implant, who had used the device an average of 1.7 yr, was examined on a battery of speech perception measures. All children demonstrated better speech perception skills with the implant than they had in the preimplant condition with hearing aids. With the Nucleus implant, 61% of the children demonstrated some open-set speech recognition and another 14% demonstrated closed-set speech recognition. Scores on the tests were corrected for guessing and a hierarchy of test difficulty was developed. The results revealed systematic differences in performance as a function of perception task and test format. The results of regression analyses, which were performed to identify predictors of success, showed that communication mode made a significant unique contribution to the variance in performance among subjects on an open-set word recognition test. When the scores of the children who used oral or total communication were compared on the full battery of tests, however, there were few significant group differences.

Variables affecting implant performance in children

This study examined the variables that contribute to the large individual differences in the speech perception skills of children with the Nucleus multichannel cochlear implant. Sixty‐one children were tested on four measures of speech perception: two tests of closed‐set word recognition, one test of open‐set recognition of phrases, and one open‐set monosyllabic word test, scored on the basis of the percentage of phonemes as well as words identified correctly. The results of a series of multiple regression analyses revealed that the variables of processor type, duration of deafness, communication mode, age at onset of deafness, length of implant use, and age implanted accounted for roughly 35% of the variance on two tests of closed‐set word recognition, and 40% of the variance on measures that assessed recognition of words or phomenes in an open set. Length of implant use accounted for the most variance on all of the speech perception measures.

Assessing Cochlear Implant Benefit in Very Young Children

3. Tyler RS, Fryauf-Bertschy H, Kelsay DMR, Gantz BJ, Woodworth GP, Parkinson A. Speech perception by prelingually deaf children using cochlear implants. Otolaryngol Head Neck Surg 1997;117:1807. 4. Balkany T, Hodges AV, Luntz M. Update on cochlear implantation. Otolaryngol Clinic North Am 1996;29:277-89. 5. Miyamoto R, Osberger M, Todd S, et al. Variables affecting implant performance in children. Laryngoscope 1994;104:1120-4. 6. Harrison R, Nedzelski J, Picton N, et al. The Paediatric Cochlear Implant Program at the Hospital for Sick Children, Toronto. J Otolaryngol 1997;26:180-7. 7. De Jong A, Nedzelski J, Papsin B. Surgical outcome measures of pédiatrie cochlear implantation. J Otolaryngol 1998;27:26-30. 8. Dawson PW, Blarney PJ, Rowland LC, et al. Cochlear implants in children, adolescents, and prelinguistically deafened adults: speech perception. J Speech Hear Res 1992;35:401-17.

Cochlear implantation of children with minimal open-set speech recognition skills

Objective: The purpose of this study was to evaluate the postoperative performance of 12 children who demonstrated some open‐set speech recognition skills before receiving a Nucleus multichannel cochlear implant with a view toward expanding the selection criteria for cochlear implant candidacy to include children who derive minimal benefit from amplification. Design: Pre‐ and postoperative performance of two groups of children were compared. Group 1 consisted of 12 children who demonstrated some open‐set speech recognition skills before receiving a Nucleus multichannel cochlear implant (Borderline group). Group 2 consisted of 12 children who demonstrated no open‐set speech recognition skills before implantation with a Nucleus device (Traditional group). In all children, candidacy was determined based on preimplant binaural aided performance. For most subjects, the poorer ear was selected for implantation. Mean pre‐ and postoperative speech recognition scores of the Borderline subjects were compared to determine the benefit provided by their cochlear implants. Secondly, matched‐pair analyses were used to compare the mean speech recognition scores obtained by the Borderline and Traditional subjects. Results: The scores of the Borderline group improved significantly on five of six speech recognition measures when 6 mo postoperative scores obtained with the implant were compared with preoperative test scores obtained with hearing aids. By the 12 mo postoperative interval, the scores of the Borderline group had improved significantly (p < 0.05) on all six measures. In contrast, scores obtained by the Traditional group had improved significantly on three of six measures at both the 6 and 12 mo postoperative intervals. Comparison of postoperative test scores revealed that the Borderline group scored significantly higher than the Traditional group on three of six measures at the 6 mo test interval and on six of six measures at the 12 mo test interval (p < 0.05). Conclusions: The findings of this study indicate that both groups derive significant benefit from their cochlear implants. Although the mean preoperative audiograms for the implanted ears did not differ significantly for the two groups of subjects, members of the Borderline group exhibited significantly better speech recognition skills than the Traditional group during the first year after implantation. These findings suggest that the increased auditory experience of the Borderline subjects positively influenced their performance with a cochlear implant. The authors advocate that the selection criteria used to determine pediatric cochlear implant candidacy be broadened to include consideration of children who demonstrate minimal open‐set speech recognition skills.

Effects of Preoperative Electrical Stimulability and Historical Factors on Performance with Multichannel Cochlear Implant

We investigated the relationship between results of preoperative transtympanic electrical promontory stimulation, duration of deafness, postoperative implanted psychophysical results, and postoperative speech and speech sound recognition as indicated by a battery of five tests. Our subjects were 10 patients implanted with the Cochlear Corporation multielectrode implant, 1 year postimplantation, with a minimum of 17 active electrodes programmed in the bipolar + 1 mode. The results indicated that preoperative promontory thresholds, the slope of the threshold function, and the duration of auditory deprivation are excellent predictors of postoperative speech and speech sound recognition in the auditory (processor alone) mode. These results have significant implications for patient selection and counseling.

Clinical Trial of the Clarion® Cochlear Implant in Children:

Preoperative and postoperative efficacy results are reported for the first 58 children with 18 months of implant experience in the United States. A within-subjects repeated-measures design was used to compare preoperative performance with hearing aids to postoperative performance with the CLARION® Multi-Strategy™ Cochlear Implant. The results revealed significant improvement over time on all speech perception measures. Higher scores and faster rates of progress were demonstrated by the children who used oral communication compared to children who used total communication, especially older children. The overall results suggest higher levels of performance and more rapid progress in the development of listening skills than has been reported in previous clinical trials with children. The latter finding appears to be due to advances in implant technology and changes in the demographic characteristics of the study groups.

A comparison of round-window and transtympanic promontory electric stimulation in cochlear implant candidates.

We compared within-subjects electrical thresholds and dynamic ranges obtained with direct round-window and transtympanic promontory stimulation carried out preoperatively in 12 patients who were candidates for a cochlear implant. Square waves with frequencies of 50, 100, 200, and 400 Hz were delivered in a 50% duty cycle to both sites in each patient. With the exception of threshold at 50 Hz (promontory thresholds were lower than round-window thresholds), there were no statistically significant differences for either thresholds or dynamic ranges between the two sites of stimulation. There was a general trend for round-window thresholds to be lower and dynamic ranges larger, especially for the higher frequencies of stimulation. Mean threshold slopes for the two sites of stimulation were nearly identical.

Speech perception results in children using the Clarion Multi-Strategy Cochlear Implant.

tation, in that one quarter of the children in the Nottingham program have been fitted with an FM system in conjunction with their body-worn speech processors. It is expected that the number of FM users will increase as the childrens educational setting changes with age. Therefore, because of the ESPrits lack of FM input, 2 processors (ESPrit and SPrint) are currently required for any child who uses the ESPrit and an FM radio hearing aid, and this adds to the cost borne by implant programs. An acoustic cochlear implant-FM coupler could be developed and used as an interim measure before the system becomes fully compatible with normal FM input. A further limitation of the ESPrit is that there is no visible check of processor function for inexperienced users.

Adult and Pediatric Cochlear Implant Programs at the University of Michigan

The Cochlear Implant Program at the University of Michigan has evolved over the past several years and is strongly dependent on a team approach to clinical care. Members of the team work closely to...