Biomedical subjects
Publications and source records attributed to R S Tyler.
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OBJECTIVE: This study aimed to determine the effects of preoperative speech reception on postoperative speech recognition with a cochlear implant and to develop a statistical index allowing prediction of postoperative speech recognition before implantation. STUDY DESIGN: The study design was a retrospective case review with statistical modeling. SETTING: The study was conducted at a tertiary referral center with an associated Veteran's Administration hospital. PATIENTS: Postlingually deafened adults with and without residual speech reception participated. INTERVENTION: Cochlear implantation with Cochlear Corporation CI-22 and CI-24 devices was performed. MAIN OUTCOME MEASURES: Monosyllabic word recognition was measured. RESULTS: Duration of deafness and preoperative sentence recognition are both significant predictors of word recognition with a cochlear implant and can account for 80% of the variance in word recognition. CONCLUSIONS: Cochlear implant outcomes are variable but predictable within specific ranges.
Sixteen experienced cochlear implant patients with a wide range of speech-perception abilities received the SPEAK processing strategy in the Nucleus Spectra-22 cochlear implant. Speech perception was assessed in quiet and in noise with SPEAK and with the patients' previous strategies (for most, Multipeak) at the study onset, as well as after using SPEAK for 6 months. Comparisons were made within and across the two test sessions to elucidate possible learning effects. Patients were also asked to rate the strategies on seven speech recognition and sound quality scales. After 6 months' experience with SPEAK, patients showed significantly improved mean performance on a range of speech recognition measures in quiet and noise. When mean subjective ratings were compared over time there were no significant differences noted between strategies. However, many individuals rated the SPEAK strategy better for two or more of the seven subjective measures. Ratings for "appreciation of music" and "quality of my own voice" in particular were generally higher for SPEAK. Improvements were realized by patients with a wide range of speech perception abilities, including those with little or no open-set speech recognition.
OBJECTIVE: To determine the long-term psychological outcome of postlingually deafened adults who received multichannel cochlear implants and to relate the psychological outcome to audiological outcome. DESIGN: Thirty-seven recipients of multichannel cochlear implants who participated in a prospective clinical trial completed psychological assessments before implantation and at regularly scheduled follow-ups through 54 mo of implant use. Standardized measures of affect, social function, and personality were used, and scores on these measures were correlated with asymptotic scores on several audiological measures. RESULTS: Evidence of significant improvement on measures of loneliness, social anxiety, and distress were obtained within a year after implantation and throughout the duration of the follow-up period. For measures of assertiveness and marital satisfaction, improvement was apparent only after long-term implant use. Although favorable changes on the Minnesota Multiphasic Personality Inventory (MMPI) Depression Scale were evidenced only in the initial follow-up period, improvements on the MMPI Paranoia and Social Introversion Scales persisted throughout the 54 mo follow-up. CONCLUSION: Multichannel cochlear implant use is associated with long-term psychological benefit. Correlations between audiological outcome and psychological outcome, however, suggested that the relation between audiological benefit and psychological benefit is not simple.
Vowel perception ability for 16 prelingually deafened children using Nucleus 22-channel cochlear implants was studied at 12, 24, and 36 months postimplantation. Information transmission analysis was used to evaluate the effectiveness of the implants in conveying the essential cues required for accurate vowel identification and whether the cues used varied with experience or device use. Individual vowel identification varied widely with mean scores significantly improving between 12 and 24 months but not between 24 and 36 months. Information transmission scores for all vowel features (fronting, height, duration, and diphthongization) increased dramatically between 12 and 36 months. Results indicated that vowel height and vowel fronting were the most salient features for the subject group. There were no differences in the pattern of confusions made across test sessions or across groups when divided into "poor" and "good" users. However, there was evidence that the "good" users made better use of higher frequency formant information than the "poor" users. The results of the present study add to the accumulation of evidence pointing to the great benefit that cochlear implantation can provide to prelingually deafened children. Overall performance for the vowel recognition test used in this study was quite high and analysis of the childrens' errors suggested that their cochlear implants were reasonably effective at conveying the most essential spectral information required for vowel discrimination.
OBJECTIVE: This study aimed to compare open-set speech perception of single-channel with multichannel cochlear implants in the same ear of postlingually deafened adults. STUDY DESIGN: The study design was a retrospective case and literature review. SETTING: The study was conducted at a tertiary referral center with an associated veterans administration hospital. PATIENTS: Postlingually deafened adults with at least 6 months of experience with a single-channel cochlear implant were studied. INTERVENTION: Replacement of a single-channel with a multichannel cochlear implant in the same ear was performed. MAIN OUTCOME MEASURES: Open-set word and sentence perception scores at least 6 months after single-channel implantation and multichannel reimplantation were measured. RESULTS: Six of six patients had substantial improvement in open-set speech recognition after reimplantation of the same ear. CONCLUSIONS: Removal of a functioning single-channel implant and replacement with a multichannel device are appropriate in postlingually deafened adults who desire better speech recognition.
In this investigation we measured the performance of 50 prelingually deaf children on several speech perception tests. Children were from 2 to 15 years of age, and some children were tested with as much as 5 years of cochlear implant use. Speech perception tests included the recognition of stress pattern, consonants, vowels, words, and sentences. The audiovisual perception of consonants was also measured. Average results indicated that gains were being made in the perception of stress and words in a closed-set context within 1 year from implantation. The perception of words in an open-set context demonstrated much slower increases over time. Large individual differences were observed. Some preliminary data suggest that children who receive implants before the age of 4 years obtain higher scores, on average, than children who receive implants after the age of 5 years. Some children become part-time users or nonusers of their cochlear implants. The average results from 18 congenitally deaf children were significantly higher than the average results from 12 children with prelingually acquired deafness after 3 years of implant use. Information on vowel and consonant features shows increases in performance after 2 years of cochlear implant use, with the exception of the place feature. For this feature, no changes were observed. Vision-alone testing indicated that lipreading performance increased over time. An audiovisual enhancement provided by the cochlear implant was observed for all features.
This study focused on long-term speech perception performances of 34 prelingually deafened children who received multichannel cochlear implants manufactured by Cochlear Corporation. The children were grouped by the age at which they received cochlear implants and were characterized by the amount of time they used their device per day. A variety of speech perception tests were administered to the children at annual intervals following the connection of the external implant hardware. No significant differences in performance are evident for children implanted before age 5 compared to children implanted after age 5 on closed-set tests of speech perception ability. All children demonstrated an improvement in performance compared to the pre-operative condition. Open-set word recognition performance is significantly better for children implanted before age 5 compared to children implanted after age 5 at the 36-month test interval and the 48-month test interval. User status, defined by the amount of daily use of the implant, significantly affects all measures of speech perception performance except pattern perception.
This study examined the average and individual performance over time of 49 adult cochlear implant subjects. Subjects were randomly assigned to receive either the Ineraid cochlear implant, with analog processing, or the Nucleus cochlear implant, with feature-extraction processing. All subjects had postlingual profound bilateral sensorineural hearing loss and received no significant benefit from hearing aids before implantation. Group data were examined in two ways. First, only subjects who had complete data over the test period were examined. Second, an analysis of all available data was carried out by mixed linear-model analysis. In this analysis, to account for missed follow-ups at the planned intervals, data consisting of the observations closest in time to the planned test times were modeled by natural splines with knots at the planned follow-up times. Contrasts between all pairs of planned follow-up times for each device were tested, as were contrasts between devices at each planned follow-up time. Results indicated little difference between the performance of the Ineraid and Nucleus subjects in their level of performance or their rate of learning. Postimplantation performance was typically superior to preimplantation performance within 9 months, and continued to improve up to 18-30 months depending on the speech perception measure. In some subjects, improvements in speech perception measures were observed up to four or five years postimplantation. There was also evidence that three subjects had a decrement in overall speech perception performance, although their postimplantation scores were always higher than their preimplantation scores. In at least one subjects this was likely a result of age-related cognition decrements.
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OBJECTIVE: To examine whether children perform better when they receive cochlear implants when they are 2 to 4 years of age than when they are older, and to determine whether 4-year performance can be predicted from 1-year results. METHOD: Children in two age groups (2 to 4, 4 to 9 years) were tested for performance, and the age groups were compared. Children were also tested 1 and 4 years after implantation. RESULTS: The results suggest that the "implanted young" group scored higher than the "implanted old" group after 36 months, and that 1-year performance is helpful in predicting 4-year performance. CONCLUSION: It may be desirable for children to undergo implantation when they are under 2 years of age, provided that appropriate selection criteria can be determined.