Cochlear Implant Electrode Array Design and Speech Understanding.

OBJECTIVE: Cochlear implant electrode arrays are categorized based on their design as lateral wall (LW) and perimodiolar (PM) electrode arrays. The objective of this study was to investigate the effect of LW versus PM designs on postoperative speech perception across multiple manufacturers and over long follow-up durations. DESIGN: Retrospective cohort study. SETTING: Single academic medical center. PARTICIPANTS: A total of 478 adult cochlear implant recipients, implanted between the years 1992 and 2017. INTERVENTIONSS: PM versus LW cochlear implants. MAIN OUTCOMES AND MEASURES: Postoperative Consonant-Nucleus-Consonant Word (CNC-w) and Hearing in Noise Test (HINT) scores between 6 months and 5 years. RESULTS: Across 478 patients, approximately one-third received LW (n = 176, 36.8%), whereas 302 patients received a PM array (63.2%). The PM group had higher CNC-w scores from 6 months to 2 years (52 [interquartile range, 38-68] versus 48 [31-62], p = 0.036) and from 2 to 5 years (58 [43-72] versus 48 [33-66], p < 0.001). Multivariable analysis of patient-averaged scores indicated that the PM group had greater improvement from preoperative scores at all time points after the initial 6 months for both CNC-w ( ß = 4.4 [95% confidence interval, 0.6-8.3], p = 0.023) and HINT testing ( ß = 4.5 [95% confidence interval, 0.3-8.7], p = 0.038). CONCLUSIONS: This study indicates that PM electrode arrays are associated with small increases in postoperative speech perception scores, relative to LW arrays, when assessed across manufacturers, over long time durations, and using multiple outcome instruments. These findings may help guide surgeon selection and patient counseling of cochlear implant arrays.

Cochlear implantation in unilateral hearing loss: impact of short- to medium-term auditory deprivation.

Introduction: Single sided deafness (SSD) results in profound cortical reorganization that presents clinically with a significant impact on sound localization and speech comprehension. Cochlear implantation (CI) has been approved for two manufacturers' devices in the United States to restore bilateral function in SSD patients with up to 10 years of auditory deprivation. However, there is great variability in auditory performance and it remains unclear how auditory deprivation affects CI benefits within this 10-year window. This prospective study explores how measured auditory performance relates to real-world experience and device use in a cohort of SSD-CI subjects who have between 0 and 10 years of auditory deprivation. Methods: Subjects were assessed before implantation and 3-, 6-, and 12-months post-CI activation via Consonant-Nucleus-Consonant (CNC) word recognition and Arizona Biomedical Institute (AzBio) sentence recognition in varying spatial speech and noise presentations that simulate head shadow, squelch, and summation effects (S0N0, SSSDNNH, SNHNSSD; 0 = front, SSD = impacted ear, NH = normal hearing ear). Patient-centered assessments were performed using Tinnitus Handicap Inventory (THI), Spatial Hearing Questionnaire (SHQ), and Health Utility Index Mark 3 (HUI3). Device use data was acquired from manufacturer software. Further subgroup analysis was performed on data stratified by <5 years and 5-10 years duration of deafness. Results: In the SSD ear, median (IQR) CNC word scores pre-implant and at 3-, 6-, and 12-months post-implant were 0% (0-0%), 24% (8-44%), 28% (4-44%), and 18% (7-33%), respectively. At 6 months post-activation, AzBio scores in S0N0 and SSSDNNH configurations (n = 25) demonstrated statistically significant increases in performance by 5% (p = 0.03) and 20% (p = 0.005), respectively. The median HUI3 score was 0.56 pre-implant, lower than scores for common conditions such as anxiety (0.68) and diabetes (0.77), and comparable to stroke (0.58). Scores improved to 0.83 (0.71-0.91) by 3 months post-activation. These audiologic and subjective benefits were observed even in patients with longer durations of deafness. Discussion: By merging CI-associated changes in objective and patient-centered measures of auditory function, our findings implicate central mechanisms of auditory compensation and adaptation critical in auditory performance after SSD-CI and quantify the extent to which they affect the real-world experience reported by individuals.

Longitudinal Auditory Benefit for Elderly Patients After Cochlear Implant for Bilateral Hearing Loss, Including Those Meeting Expanded Centers for Medicare & Medicaid Services Criteria.

OBJECTIVE: To examine the effect of patient age on longitudinal speech understanding outcomes after cochlear implantation (CI) in bilateral hearing loss. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary academic center. PATIENTS: One thousand one hundred five adult patients with bilateral hearing loss receiving a unilateral CI between 1987 and 2022InterventionsNone. MAIN OUTCOME MEASURES: Postoperative speech recognition outcomes, including AzBio sentences, consonant-nucleus-consonant word, and Hearing in Noise Test in quiet were analyzed at short-term (<2 yr), medium-term (2-8 y), and long-term (>8 yr) term postoperative intervals. RESULTS: Eighty-six very elderly (>80 yr), 409 elderly (65-80 yr), and 709 nonelderly (18-65 yr) patients were included. Short-term postoperative AzBio scores demonstrated similar magnitude of improvement relative to preoperative scores in the very elderly (47.6, 95% confidence interval [CI], 28.9-66.4), elderly (49.0; 95% CI, 39.2-58.8), and nonelderly (47.9; 95% CI, 35.4-60.4). Scores for those older than 80 years remained stable after 2 years after implant, but in those 80 years or younger, scores continued to improve for up to 8 years (elderly: 6.2 [95% CI, 1.5-12.4]; nonelderly: 9.9 [95% CI, 2.1-17.7]) after implantation. Similar patterns were observed for consonant-nucleus-consonant word scores. Across all age cohorts, patients with preoperative Hearing in Noise Test scores between 40 and 60% had similar scores to those with preoperative scores of less than 40%, at short-term (82.4, 78.9; 95% CI, -23.1 to 10.0), medium-term (77.2, 83.9; 95% CI, -15.4 to 8.2), or long-term (73.4, 71.2; 95% CI, -18.2 to 12.2) follow-up. CONCLUSIONS: Patients older than 80 years gain significant and sustained auditory benefit after CI, including those meeting expanded Centers for Medicare & Medicaid Service criteria for implantation. Patients younger than 80 years demonstrated continued improvement over longer periods than older patients, suggesting a role of central plasticity in mediating CI outcomes as a function of age.

Are Speech Perception Scores in Cochlear Implant Recipients Consistent Across Different Tests?

OBJECTIVE: Cochlear implant (CI) candidacy and postoperative outcomes are assessed using sets of speech perception tests that vary from center to center, limiting comparisons across institutions and time periods. The objective of this study was to determine if scores on one speech perception test could be reliably predicted from scores on another test. STUDY DESIGN: Arizona Biomedical (AzBio) Sentence Test, Consonant-Nucleus-Consonant word (CNCw), and Hearing in Noise Test (HINT) scores in quiet for the implanted ear were collected for individuals who received a CI between 1985 and 2019. Scores collected during the same testing session were analyzed using Bland-Altman plots to assess agreement between testing methods. Simple linear regression with logit transformation was used to generate predictive functions and 95% confidence intervals for expected mean and individual scores. SETTING: Single academic medical center. PATIENTS: A total of 1,437 individuals with a median age of 59.9 years (range, 18-95 yr) and 46% (654 of 1,437) male. INTERVENTIONS: N.A. MAIN OUTCOME MEASURES: Agreement as a function of test score, mean, variance, and correlation coefficients. RESULTS: A total of 2,052 AzBio/CNCw, 525 AzBio/HINT, and 7,187 CNCw/HINT same-session score pairings were identified. Pairwise test comparisons demonstrated limited agreement between different tests performed in the same session, and a score correlation between different speech tests revealed large variances. CONCLUSION: Transformation functions between test batteries were predictive of mean scores but performed poorly for prediction of individual scores. Point-wise comparisons of scores across CI test batteries should be used with caution in clinical and research settings.