Cochlear implantation with hearing preservation yields significant benefit for speech recognition in complex listening environments.

OBJECTIVE: The aim of this study was to assess the benefit of having preserved acoustic hearing in the implanted ear for speech recognition in complex listening environments. DESIGN: The present study included a within-subjects, repeated-measures design including 21 English-speaking and 17 Polish-speaking cochlear implant (CI) recipients with preserved acoustic hearing in the implanted ear. The patients were implanted with electrodes that varied in insertion depth from 10 to 31 mm. Mean preoperative low-frequency thresholds (average of 125, 250, and 500 Hz) in the implanted ear were 39.3 and 23.4 dB HL for the English- and Polish-speaking participants, respectively. In one condition, speech perception was assessed in an eight-loudspeaker environment in which the speech signals were presented from one loudspeaker and restaurant noise was presented from all loudspeakers. In another condition, the signals were presented in a simulation of a reverberant environment with a reverberation time of 0.6 sec. The response measures included speech reception thresholds (SRTs) and percent correct sentence understanding for two test conditions: CI plus low-frequency hearing in the contralateral ear (bimodal condition) and CI plus low-frequency hearing in both ears (best-aided condition). A subset of six English-speaking listeners were also assessed on measures of interaural time difference thresholds for a 250-Hz signal. RESULTS: Small, but significant, improvements in performance (1.7-2.1 dB and 6-10 percentage points) were found for the best-aided condition versus the bimodal condition. Postoperative thresholds in the implanted ear were correlated with the degree of electric and acoustic stimulation (EAS) benefit for speech recognition in diffuse noise. There was no reliable relationship among measures of audiometric threshold in the implanted ear nor elevation in threshold after surgery and improvement in speech understanding in reverberation. There was a significant correlation between interaural time difference threshold at 250 Hz and EAS-related benefit for the adaptive speech reception threshold. CONCLUSIONS: The findings of this study suggest that (1) preserved low-frequency hearing improves speech understanding for CI recipients, (2) testing in complex listening environments, in which binaural timing cues differ for signal and noise, may best demonstrate the value of having two ears with low-frequency acoustic hearing, and (3) preservation of binaural timing cues, although poorer than observed for individuals with normal hearing, is possible after unilateral cochlear implantation with hearing preservation and is associated with EAS benefit. The results of this study demonstrate significant communicative benefit for hearing preservation in the implanted ear and provide support for the expansion of CI criteria to include individuals with low-frequency thresholds in even the normal to near-normal range.

A Five-Year Update on the Profile of Adults Undergoing Cochlear Implant Evaluation and Surgery-Are We Doing Better?

OBJECTIVE: To characterize the influence of expanding indications on the profile of adults undergoing cochlear implantation (CI) at a high-volume CI center. STUDY DESIGN: Retrospective review. SETTING: Tertiary referral center. PATIENTS: 774 adults undergoing CI evaluation from August 2015 to August 2020. MAIN OUTCOME MEASURES: Demographics; audiometry; speech recognition; speech, spatial, and qualities of hearing scale (SSQ-12). RESULTS: Of 745 (96.3%) patients qualifying for implantation, 642 (86.6%) pursued surgery. Median age at evaluation was 69 years; 56.3% were men; 88.2% were Caucasian. Median distance to our center was 95 miles. The majority (51.8%) had public insurance (Medicare, Medicaid), followed by private (47.8%) and military (0.4%). Mean PTA, CNC, and AzBio in quiet and noise for the ear to be implanted were 85.2 dB HL, 15.0%, and 19.2% and 3.5%, respectively. Hybrid/EAS criteria were met by 138 (18.5%) CI candidates, and 436 (77.0%) unilateral CI recipients had aidable contralateral hearing for bimodal hearing configurations. Younger age (odds ratio [OR], 0.96; 95% confidence interval, 0.93-0.99) and non-Caucasian race (OR, 6.95; 95% confidence interval, 3.22-14.98) predicted candidacy. Likelihood of surgery increased for Caucasian (OR, 8.08; 95% confidence interval, 4.85-13.47) and married (OR, 2.28; 95% confidence interval, 1.50-3.47) patients and decreased for those with public insurance (OR, 0.45; 95% confidence interval, 0.29-0.69). A lower SSQ-12 score predicted both candidacy and surgery. CONCLUSION: Despite expansions in criteria, speech understanding remained extremely low at CI evaluation. Younger age and non-Caucasian race predicted candidacy, and Caucasian, married patients with private insurance and lower SSQ scores were more likely to pursue surgery.

Same-Day Patient Consultation and Cochlear Implantation: Innovations in Patient-Centered Health Care Delivery.

OBJECTIVE: To develop and implement a streamlined, patient-centered service delivery model for patients referred for cochlear implantation (CI) at a high-volume academic center. PATIENTS: CI candidate adults. INTERVENTIONS: CI, implementation of new CI delivery model. MAIN OUTCOME MEASURES: Referral-to-surgery time, patient travel burden. RESULTS: Data from 206 adults that underwent CI were used to develop a process map of the initial operational state from referral date to day of surgery (referral-to-surgery time). The initial referral-to-surgery time was 136 days on average, yet the average total work time by all involved providers was 17.6 hours. Prolonged wait times were associated with the following preoperative tasks: appointment scheduling, insurance approval, device ordering and shipment, and surgical scheduling. Patients traveled to the institution on at least two occasions for appointments. A new bundled, patient-centered CI delivery model was developed to address prolonged wait times, travel burden, and process inefficiencies. The new model implemented an interactive electronic medical record, coordinated appointments with same-day surgery, and stocked device inventory to reduce the referral-to-surgery time to 24 days-an improvement of 112 days. In the new model, new patient consultation and surgery were completed in one day, reducing the patient travel burden to the institution. CONCLUSIONS: The new CI program demonstrates that delivery innovations can have a substantial impact on measures of patient convenience and experience, and that these results are achievable without new technologies or changes in medical management. With a focus on patient-centered design, health care delivery models can be augmented to increase value for patients.

Further Evidence of the Relationship Between Cochlear Implant Electrode Positioning and Hearing Outcomes.

BACKGROUND: Postoperative imaging studies by numerous groups have revealed that final cochlear implant (CI) electrode position impacts audiological outcomes with scalar location consistently shown to be a significant factor. Modiolar proximity has been less extensively studied, and findings regarding the effect of insertion depth have been inconsistent. METHODS: Using previously developed automated algorithms, we determined CI electrode position in an Institutional Review Board-approved database of 220 CI ears. Generalized linear models (GLM) were used to analyze the relationship between audiological outcomes and factors including age, duration of CI use, device type, and electrode position. RESULTS: For precurved arrays, GLM revealed that scalar position, modiolar proximity, base insertion depth, and sex were significant factors for Consonant-Nucleus-Consonant (CNC) words (R = 0.43, p < 0.001, n = 92 arrays), while scalar position, modiolar proximity, age, and postlingual onset of deafness were significant for Bamford-Kawal-Bench Sentences in Noise (BKB-SIN) (R = 0.51, p < 0.001, n = 85) scores. Other factors were not significant in the final model after controlling for these variables. For straight arrays, we found the insertion depth, postlingual deafness, and length of CI use to be highly significant (R = 0.47, p < 0.001) factors for CNC words (91 arrays), while for BKB-SIN scores the most significant (R = 0.47, p < 0.001) factors were insertion depth, younger age, and postlingual deafness (89 arrays). CONCLUSION: Our results confirm the significance of electrode positioning in audiological outcomes. The most significant positional predictors of outcome for precurved arrays were full scala tympani (ST) insertion and the modiolar distance, while for the lateral wall arrays the depth of insertion was the most significant factor.

Speech recognition materials and ceiling effects: considerations for cochlear implant programs.

Cochlear implant recipients have demonstrated remarkable increases in speech perception since US FDA approval was granted in 1984. Improved performance is due to a number of factors including improved cochlear implant technology, evolving speech coding strategies, and individuals with increasingly more residual hearing receiving implants. Despite this evolution, the same recommendations for pre- and postimplant speech recognition testing have been in place for over 10 years in the United States. To determine whether new recommendations are warranted, speech perception performance was assessed for 156 adult, postlingually deafened implant recipients as well as 50 hearing aid users on monosyllabic word recognition (CNC) and sentence recognition in quiet (HINT and AzBio sentences) and in noise (BKB-SIN). Results demonstrated that for HINT sentences in quiet, 28% of the subjects tested achieved maximum performance of 100% correct and that scores did not agree well with monosyllables (CNC) or sentence recognition in noise (BKB-SIN). For a more difficult sentence recognition material (AzBio), only 0.7% of the subjects achieved 100% performance and scores were in much better agreement with monosyllables and sentence recognition in noise. These results suggest that more difficult materials are needed to assess speech perception performance of postimplant patients - and perhaps also for determining implant candidacy.

Participant-generated Cochlear Implant Programs: Speech Recognition, Sound Quality, and Satisfaction.

OBJECTIVE: To determine whether patient-derived programming of one's cochlear implant (CI) stimulation levels may affect performance outcomes. BACKGROUND: Increases in patient population, device complexity, outcome expectations, and clinician responsibility have demonstrated the necessity for improved clinical efficiency. METHODS: Eighteen postlingually deafened adult CI recipients (mean = 53 years; range, 24-83 years) participated in a repeated-measures, within-participant study designed to compare their baseline listening program to an experimental program they created. RESULTS: No significant group differences in aided sound-field thresholds, monosyllabic word recognition, speech understanding in quiet, speech understanding in noise, nor spectral modulation detection (SMD) were observed (p > 0.05). Four ears (17%) improved with the experimental program for speech presented at 45 dB SPL and two ears (9%) performed worse. Six ears (27.3%) improved significantly with the self-fit program at +10 dB signal-to-noise ratio (SNR) and four ears (26.6%) improved in speech understanding at +5 dB SNR. No individual scored significantly worse when speech was presented in quiet at 60 dB SPL or in any of the noise conditions tested. All but one participant opted to keep at least one of the self-fitting programs at the completion of this study. Participants viewed the process of creating their program more favorably (t = 2.11, p = 0.012) and thought creating the program was easier than the traditional fitting methodology (t = 2.12, p = 0.003). Average time to create the self-fit program was 10 minutes, 10 seconds (mean = 9:22; range, 4:46-24:40). CONCLUSIONS: Allowing experienced adult CI recipients to set their own stimulation levels without clinical guidance is not detrimental to success.

Hearing Preservation Outcomes With a Mid-Scala Electrode in Cochlear Implantation.

OBJECTIVE: To evaluate hearing preservation (HP) outcomes in adult cochlear implant recipients with a mid-scala electrode. SETTING: Tertiary academic center. PATIENTS: Adult patients implanted with a mid-scala electrode between May 2013 and July 2015. INTERVENTIONS: Cochlear implantation. MAIN OUTCOME MEASURE(S): Age, sex, surgical approach, residual hearing changes post cochlear implantation, HP rates using different published classifications, and speech perception scores. RESULTS: Fifty ears for 47 patients (mean age, 58.2 yr; range, 23-86) were implanted with the electrode. Recognizing that not all patients were true HP candidates and/or underwent generally accepted HP surgical techniques, 39 ears had preoperative low-frequency hearing (audiometric threshold ≤ 85dB HL at 250Hz), 24 preserved acoustic hearing postoperatively (75.0%). Patients who had preserved acoustic hearing were implanted via round window (N = 18), extended round window (N = 4), or via cochleostomy (N = 2) approaches. Mean threshold elevation for low-frequency pure-tone average (125, 250, and 500  Hz) was 20.2  dB after surgery. 43.8% of patients had aidable low-frequency hearing at activation, 30.0% at 6-months postoperatively, and 30.8% 1-year postopera tively. Using a formula outlined by Skarzynski and colleagues, at 6-months postoperatively, 15.0% of patients had complete HP, whereas 40.0% had partial HP. At 1-year, these percentages decreased to 0% and 38.5%, respectively. Age, type of approach, and perioperative steroid use were not correlated with HP outcomes at activation and 6-months postoperatively (p > 0.05). CONCLUSION: The mid-scala electrode evaluated allows preservation of low-frequency hearing in patients undergoing cochlear implantation at rates and degrees of preservation close to other reports in the cochlear implant literature.

Conversion disorder: a missed diagnosis leading to cochlear reimplantation.

OBJECTIVE: To report a case of a patient presenting with presumed cochlear implant (CI) device failure that underwent revision surgery and was ultimately diagnosed with conversion disorder. STUDY DESIGN: Clinical capsule report. SETTING: Tertiary academic referral center. PATIENT: A pediatric patient with Waardenburg syndrome underwent unilateral CI at the age of 6 years for bilateral profound sensorineural hearing loss. During the following 2 years, the patient experienced subjective symptoms of device malfunction including abnormal sounds and intermittent loss of signal despite external component exchange. The patient subsequently underwent revision surgery only to have persistent intermittent complaints. Given the severity of the symptoms, the patient underwent a second reimplantation procedure. Extensive device testing by our institutional implant program and the manufacturer failed to reveal any causal device defects. INTERVENTIONS AND RESULTS: Given the ongoing but inconsistent subjective complaints and normal device testing, the patient was referred for psychiatric consultation to evaluate for a nonorganic underlying cause. The patient was subsequently diagnosed with conversion disorder and successfully managed with ongoing psychiatric counseling and close follow-up with our CI program. CONCLUSION: This represents the first report of a patient presenting with symptoms of device failure, who underwent revision surgery and was ultimately found to have conversion disorder. Although rare, conversion disorder should be considered in the differential diagnosis of patients presenting with symptoms of device malfunction and normal integrity testing particularly among those with significant psychosocial stressors or a history of psychiatric illness. Thorough device testing and in-depth psychological evaluation is required for diagnosis, and close multidisciplinary follow-up with the CI team and psychiatrist is crucial.