Do Patients Benefit From a Cochlear Implant When They Qualify Only in the Presence of Background Noise?

Cochlear Implant Qualification in Noise Versus Quiet: Do Patients Demonstrate Similar Postoperative Benefits?

OBJECTIVE

To assess patient factors, audiometric performance, and patient-reported outcomes in cochlear implant (CI) patients who would not have qualified with in-quiet testing alone.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

METHODS

Adult CI recipients implanted between 2012 and 2022 were identified. Patients with preoperative AzBio Quiet > 60% in the implanted ear, requiring multitalker babble to qualify, comprised the in-noise qualifying (NQ) group. NQ postoperative performance was compared with the in-quiet qualifying (QQ) group using CNC, AzBio Quiet, and AzBio +5 dB signal-to-noise ratio. Speech, Spatial and Qualities of Hearing Scale (SSQ), Cochlear Implant Quality of Life scale (CIQOL-10), and daily device usage were also compared between the groups.

RESULTS

The QQ group (n = 771) and NQ group (n = 67) were similar in age and hearing loss duration. NQ had higher average preoperative and postoperative speech recognition scores. A larger proportion of QQ saw significant improvement in CNC and AzBio Quiet scores in the CI-only listening condition (eg, CI-only AzBio Quiet: 88% QQ vs 51% NQ, P < .001). Improvement in CI-only AzBio +5 dB and in all open set testing in the best-aided binaural listening condition was similar between groups (eg, Binaural AzBio Quiet 73% QQ vs 59% NQ, P = .345). Postoperative SSQ ratings, CIQOL scores, and device usage were also equivalent between both groups.

CONCLUSION

Patients who require in-noise testing to meet CI candidacy demonstrate similar improvements in best-aided speech perception and patient-reported outcomes as in-QQ, supporting the use of in-noise testing to determine CI qualification for borderline CI candidates.

Enhancing Cochlear Implant Outcomes across Age Groups: The Interplay of Forward Focus and Advanced Combination Encoder Coding Strategies in Noisy Conditions

Background: Hearing in noise is challenging for cochlear implant users and requires significant listening effort. This study investigated the influence of ForwardFocus and number of maxima of the Advanced Combination Encoder (ACE) strategy, as well as age, on speech recognition threshold and listening effort in noise. Methods: A total of 33 cochlear implant recipients were included (age ≤ 40 years: n = 15, >40 years: n = 18). The Oldenburg Sentence Test was used to measure 50% speech recognition thresholds (SRT50) in fluctuating and stationary noise. Speech was presented frontally, while three frontal or rear noise sources were used, and the number of ACE maxima varied between 8 and 12. Results: ForwardFocus significantly improved the SRT50 when noise was presented from the back, independent of subject age. The use of 12 maxima further improved the SRT50 when ForwardFocus was activated and when noise and speech were presented frontally. Listening effort was significantly worse in the older age group compared to the younger age group and was reduced by ForwardFocus but not by increasing the number of ACE maxima. Conclusion: Forward Focus can improve speech recognition in noisy environments and reduce listening effort, especially in older cochlear implant users.

American Cochlear Implant Alliance Task Force: Recommendations for Determining Cochlear Implant Candidacy in Adults

The indications for cochlear implantation have expanded over time due to evidence demonstrating identification and implantation of appropriate cochlear implant (CI) candidates lead to significant improvements in speech recognition and quality of life (QoL). However, clinical practice is variable, with some providers using outdated criteria and others exceeding current labeled indications. As a results, only a fraction of those persons who could benefit from CI technology receive it. This document summarizes the current evidence for determining appropriate referrals for adults with bilateral hearing loss into CI centers for formal evaluation by stressing the importance of treating each ear individually and a "revised 60/60 rule". By mirroring contemporary clinical practice and available evidence, these recommendations will also provide a standardized testing protocol for CI candidates using a team-based approach that prioritizes individualized patient care. This manuscript was developed by the Adult Cochlear Implantation Candidacy Task Force of the American Cochlear Implant Alliance using review of the existing literature and clinical consensus. LEVEL OF EVIDENCE: N/A Laryngoscope, 134:S1-S14, 2024.

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.

Influence of Age on Speech Recognition in Noise and Hearing Effort in Listeners with Age-Related Hearing Loss

The aim of this study was to measure how age affects the speech recognition threshold (SRT50) of the Oldenburg Sentence Test (OLSA) and the listening effort at the corresponding signal-to-noise ratio (SNRcut). The study also investigated the effect of the spatial configuration of sound sources and noise signals on SRT50 and SNRcut. To achieve this goal, the study used olnoise and icra5 noise presented from one or more spatial locations from the front and back. Ninety-nine participants with age-related hearing loss in the 18-80 years age range, specifically in the 18-30, 31-40, 41-50, 51-60, 61-70, and 71-80 age groups, participated in this study. Speech recognition and listening effort in noise were measured and compared between the different age groups, different spatial sound configurations and noise signals. Speech recognition in noise decreased with age and became significant from the age group of 50-51. The decrease in SRT50 with age was greater for icra5 noise than for olnoise. For all age groups, SRT50 and SNRcut were better for icra5 noise than for olnoise. The measured age-related reference data for SRT50 and SNRcut can be used in further studies in listeners with age-related hearing loss and hearing aid or implant users.

Responsible Imputation of Missing Speech Perception Testing Data & Analysis of 4,739 Observations and Predictors of Performance

OBJECTIVE

To address outcome heterogeneity in cochlear implant (CI) research, we built imputation models using multiple imputation by chained equations (MICEs) and K-nearest neighbors (KNNs) to convert between four common open-set testing scenarios: Consonant-Nucleus-Consonant word (CNCw), Arizona Biomedical (AzBio) in quiet, AzBio +5, and AzBio +10. We then analyzed raw and imputed data sets to evaluate factors affecting CI outcome variability.

STUDY DESIGN

Retrospective cohort study of a national CI database (HERMES) and a nonoverlapping single-institution CI database.

SETTING

Multi-institutional (32 CI centers).

PATIENTS

Adult CI recipients (n = 4,046 patients).

MAIN OUTCOME MEASURES

Mean absolute error (MAE) between imputed and observed speech perception scores.

RESULTS

Imputation models of preoperative speech perception measures demonstrate a MAE of less than 10% for feature triplets of CNCw/AzBio in quiet/AzBio +10 (MICE: MAE, 9.52%; 95% confidence interval [CI], 9.40-9.64; KNN: MAE, 8.93%; 95% CI, 8.83-9.03) and AzBio in quiet/AzBio +5/AzBio +10 (MICE: MAE, 8.85%; 95% CI, 8.68-9.02; KNN: MAE, 8.95%; 95% CI, 8.74-9.16) with one feature missing. Postoperative imputation can be safely performed with up to four of six features missing in a set of CNCw and AzBio in quiet at 3, 6, and 12 months postcochlear implantation using MICE (MAE, 9.69%; 95% CI, 9.63-9.76). For multivariable analysis of CI performance prediction, imputation increased sample size by 72%, from 2,756 to 4,739, with marginal change in adjusted R2 (0.13 raw, 0.14 imputed).

CONCLUSIONS

Missing data across certain sets of common speech perception tests may be safely imputed, enabling multivariate analysis of one of the largest CI outcomes data sets to date.

Relationships Between the Auditory Nerve Sensitivity to Amplitude Modulation, Perceptual Amplitude Modulation Rate Discrimination Sensitivity, and Speech Perception Performance in Postlingually Deafened Adult Cochlear Implant Users

OBJECTIVE

This study assessed the relationships between the salience of amplitude modulation (AM) cues encoded at the auditory nerve (AN), perceptual sensitivity to changes in AM rate (i.e., AM rate discrimination threshold, AMRDT), and speech perception scores in postlingually deafened adult cochlear implant (CI) users.

DESIGN

Study participants were 18 postlingually deafened adults with Cochlear Nucleus devices, including five bilaterally implanted patients. For each of 23 implanted ears, neural encoding of AM cues at 20 Hz at the AN was evaluated at seven electrode locations across the electrode array using electrophysiological measures of the electrically evoked compound action potential (eCAP). The salience of AM neural encoding was quantified by the Modulated Response Amplitude Ratio (MRAR). Psychophysical measures of AMRDT for 20 Hz modulation were evaluated in 16 ears using a three-alternative, forced-choice procedure, targeting 79.4% correct on the psychometric function. AMRDT was measured at up to five electrode locations for each test ear, including the electrode pair that showed the largest difference in the MRAR. Consonant-Nucleus-Consonant (CNC) word scores presented in quiet and in speech-shaped noise at a signal to noise ratio (SNR) of +10 dB were measured in all 23 implanted ears. Simulation tests were used to assess the variations in correlation results when using the MRAR and AMRDT measured at only one electrode location in each participant to correlate with CNC word scores. Linear Mixed Models (LMMs) were used to evaluate the relationship between MRARs/AMRDTs measured at individual electrode locations and CNC word scores. Spearman Rank correlation tests were used to evaluate the strength of association between CNC word scores measured in quiet and in noise with (1) the variances in MRARs and AMRDTs, and (2) the averaged MRAR or AMRDT across multiple electrodes tested for each participant.

RESULTS

There was no association between the MRAR and AMRDT. Using the MRAR and AMRDT measured at only one, randomly selected electrode location to assess their associations with CNC word scores could lead to opposite conclusions. Both the results of LMMs and Spearman Rank correlation tests showed that CNC word scores measured in quiet or at 10 dB SNR were not significantly correlated with the MRAR or AMRDT. In addition, the results of Spearman Rank correlation tests showed that the variances in MRARs and AMRDTs were not significantly correlated with CNC word scores measured in quiet or in noise.

CONCLUSIONS

The difference in AN sensitivity to AM cues is not the primary factor accounting for the variation in AMRDTs measured at different stimulation sites within individual CI users. The AN sensitivity to AM per se may not be a crucial factor for CNC word perception in quiet or at 10 dB SNR in postlingually deafened adult CI users. Using electrophysiological or psychophysical results measured at only one electrode location to correlate with speech perception scores in CI users can lead to inaccurate, if not wrong, conclusions.

Outcomes in Patients Meeting Cochlear Implant Criteria in Noise but Not in Quiet

OBJECTIVE

Evaluate outcomes in cochlear implant (CI) recipients qualifying in AzBio noise but not quiet, and identify factors associated with postimplantation improvement.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary otology/neurotology clinic.

PATIENTS

This study included 212 implanted ears. The noise group comprised 23 ears with preoperative AzBio more than or equal to 40% in quiet and less than or equal to 40% in +10 signal-to-noise ratio (SNR). The quiet group included 189 ears with preoperative AzBio less than 40% in quiet. The two groups displayed similar demographics and device characteristics.

INTERVENTIONS

Cochlear implantation.

MAIN OUTCOME MEASURES

AzBio in quiet and noise.

RESULTS

Mean AzBio quiet scores improved in both the quiet group (pre-implant: 12.7%, postimplant: 67.2%, p < 0.001) and noise group (pre-implant: 61.6%, postimplant: 73.8%, p = 0.04). Mean AzBio +10 SNR also improved in the quiet group (pre-implant: 15.8%, postimplant: 59.3%, p = 0.001) and noise group (pre-implant: 30.5%, postimplant: 49.1%, p = 0.01). However, compared with the quiet group, fewer ears in the noise group achieved within-subject improvement in AzBio quiet (≥15% improvement; quiet group: 90.3%, noise group: 43.8%, p < 0.001) and AzBio +10 SNR (quiet group: 100.0%, noise group: 45.5%, p < 0.001). Baseline AzBio quiet (p < 0.001) and Consonant-Nucleus-Consonant (CNC) scores (p = 0.004) were associated with within-subject improvement in AzBio quiet and displayed a higher area under the curve than either aided or unaided pure-tone average (PTA) (both p = 0.01).

CONCLUSIONS

CI patients qualifying in noise display significant mean benefit in speech recognition scores but are less likely to benefit compared with those qualifying in quiet. Patients with lower baseline AzBio quiet scores are more likely to display postimplant improvement.

The Impact of Age on Noise Sensitivity in Cochlear Implant Recipients

OBJECTIVE

To evaluate the impact of different open set sentence recognition tests in quiet, +10 dB signal to noise ratio (SNR), and +5 dB SNR in adult cochlear implant (CI) recipients above and below 65 years of age.

STUDY DESIGN AND SETTING

Multi-institution, prospective, non-randomized, single-subject repeated measures design.

PATIENTS

Ninety six adults more than or equal to 18 years old with postlingual bilateral sensorineural hearing loss.

INTERVENTIONS

Participants received a CI532 in one ear. Speech perception measures were evaluated before and 6-months after activation.

MAIN OUTCOME MEASURES

Subjects completed consonant-nucleus-constant (CNC) words in quiet and AzBio sentences in noise using +10 and +5 dB SNR, and Montreal Cognitive Assessment (MOCA).

RESULTS

Ninety six adult patients were enrolled (n = 70 older [≥65 yr], n = 26 younger [<65 yr]). There was no difference in CNC scores (CI alone 58.4% versus 67.5%, p = 0.0857; best aided 66.7% versus 76.1%, p = 0.3357). Older adults performed worse on AzBio +10 dB SNR compared with younger patients (CI alone 37.4% versus 56.9%, p = 0.0006; best aided 51.4% versus 68.2%; p = 0.01), and in AzBio +5 dB SNR (CI alone 7.7% versus 11.2%, p = 0.0002; best aided 15.3% versus 22.3%, p = 0.0005). The magnitude of change in AzBio +10 dB SNR was significantly less in older adults in CI alone (15.3% versus 22.3%; p = 0.0493) but not best aided (21.5% versus 31.3%; p = 0.105). The magnitude of change was drastically worse in AzBio +5 dB SNR for older adults (CI alone 6.7% versus 22.1%, p = 0.0014; best aided 9.5% versus 21.5%; p = 0.0142). There was no significant difference in MOCA between the two age groups.

CONCLUSIONS

While both older and younger patients have similar outcomes with respect to CNC word scores in quiet, the addition of noise disproportionally impacts older patients. Caution should be exercised testing the elderly in noise; testing in noise may disproportionally impact performance expectations and should be more carefully considered when used for candidacy criteria and counseling. Future studies need to further investigate the disproportionate effect of noise on candidacy testing and its impact on how elderly patients are qualified.

Home-Based Speech Perception Monitoring for Clinical Use With Cochlear Implant Users

Speech-perception testing is essential for monitoring outcomes with a hearing aid or cochlear implant (CI). However, clinical care is time-consuming and often challenging with an increasing number of clients. A potential approach to alleviating some clinical care and possibly making room for other outcome measures is to employ technologies that assess performance in the home environment. In this study, we investigate 3 different speech perception indices in the same 40 CI users: phoneme identification (vowels and consonants), digits in noise (DiN) and sentence recognition in noise (SiN). The first two tasks were implemented on a tablet and performed multiple times by each client in their home environment, while the sentence task was administered at the clinic. Speech perception outcomes in the same forty CI users showed that DiN assessed at home can serve as an alternative to SiN assessed at the clinic. DiN scores are in line with the SiN ones by 3–4 dB improvement and are useful to monitor performance at regular intervals and to detect changes in auditory performance. Phoneme identification in quiet also explains a significant part of speech perception in noise, and provides additional information on the detectability and discriminability of speech cues. The added benefit of the phoneme identification task, which also proved to be easy to administer at home, is the information transmission analysis in addition to the summary score. Performance changes for the different indices can be interpreted by comparing against measurement error and help to target personalized rehabilitation. Altogether, home-based speech testing is reliable and proves powerful to complement care in the clinic for CI users.

Cochlear Implant Performance in Candidates With Moderate Hearing Loss Qualifying in Noise

OBJECTIVE

To determine postcochlear implantation performance for patients qualifying on preimplant testing in noise.

STUDY DESIGN

Retrospective chart review of cochlear implant recipients.

MAIN OUTCOME MEASURE

Performance on word and sentence testing in the implanted ear and bimodal condition were compared between pre- and postimplantation time points.

RESULTS

At 2-years postimplantation, CNC testing in quiet in the implanted ear improved from an average percent correct score of 14.0 ± 12.1% to 54.9 ± 14.8% (n = 20, p < 0.0001, d = 3.0) for those qualifying at +8, and from 23.4 ± 15.6% to 55.5 ± 19.4% (n = 28, p < 0.0001, d = 1.8) for those qualifying at +5. Likewise, AzBio in quiet in the implanted ear improved from an average % correct score of 19.9 ± 16.0% to 75.1 ± 11.8% (n = 20, p < 0.0001, d = 4.0) for those qualifying at +8, and from 46.2 ± 21.7% to 74.1 ± 21.3% (n = 27, p < 0.0001, d = 1.4) for those qualifying at +5. CNC and AzBio performance in quiet in the bimodal condition also improved with those qualifying at +8 and +5 having similar average scores at 2-years post activation. For those qualifying at +8, performance improved on CNC and AzBio in the implanted ear in 95% of patients and in the bimodal condition in 89% of patients. The proportion of patients improving on both tests for those qualifying at +5 at 2 years was 85% in the implanted ear, and 72% in the bimodal condition.

CONCLUSION

The majority of patients qualifying for cochlear implantation with the addition of noise showed improved speech perception in quiet. These data provide useful counseling tools for patients considering cochlear implantation who do not meet traditional eligibility requirements when tested in quiet.