Comparison of two cochlear implant coding strategies on speech perception.

OBJECTIVE: Assess whether differences in speech perception are observed after exclusive listening experience with high-definition continuous interleaved sampling (HDCIS) versus fine structure processing (FSP) coding strategies. METHODS: Subjects were randomly assigned at initial activation of the external speech processor to receive the HDCIS or FSP coding strategy. Frequency filter assignments were consistent across subjects. The speech perception test battery included CNC words in quiet, HINT sentences in quiet and steady noise (+10 dB SNR), AzBio sentences in quiet and a 10-talker babble (+10 dB SNR), and BKB-SIN. Assessment intervals included 1, 3, and 6 months post-activation. RESULTS: Data from 22 subjects (11 with HDCIS and 11 with FSP) were assessed over time. Speech perception performance was not significantly different between groups. DISCUSSION: Speech perception performance was not significantly different after 6 months of listening experience with the HDCIS or FSP coding strategy.

Impact of Electric Stimulation on Residual Hearing.

BACKGROUND: Candidacy criteria for cochlear implantation are expanding to include patients with substantial low-to-mid frequency hearing sensitivity. Postoperative hearing preservation has been achieved in cochlear implant recipients, though with variable outcomes. Previous investigations on postoperative hearing preservation outcomes have evaluated intraoperative procedures. There has been limited review as to whether electric stimulation influences hearing preservation. PURPOSE: The purpose of this analysis was to evaluate whether charge levels associated with electric stimulation influence postoperative hearing preservation within the first year of listening experience. RESEARCH DESIGN: Retrospective analysis of unaided residual hearing and charge levels. STUDY SAMPLE: Twenty-eight cochlear implant recipients with postoperative residual hearing in the operative ear and at least 12 mo of listening experience with electric-acoustic stimulation (EAS). DATA COLLECTION AND ANALYSIS: Assessment intervals included initial cochlear implant activation, initial EAS activation, and 3-, 6-, and 12-mo postinitial EAS activation. A masked low-frequency bone-conduction (BC) pure-tone average (PTA) was calculated for all participants at each assessment interval. Charge levels for each electrode were determined using the most comfortable loudness level and pulse width values. Charge levels associated with different regions of the electrode array were compared to the change in the low-frequency BC PTA between two consecutive intervals. RESULTS: Charge levels had little to no association with the postoperative change in low-frequency BC PTA within the first year of listening experience. CONCLUSIONS: Electric charge levels do not appear to be reliably related to the subsequent loss of residual low-frequency hearing in the implanted ear within the first year of EAS listening experience.

Influence of age at revision cochlear implantation on speech perception outcomes.

IMPORTANCE: This study reviewed whether advanced age should be a consideration when revision cochlear implantation is warranted. OBJECTIVE: To examine whether age at revision cochlear implantation is related to postrevision speech perception performance. DESIGN, SETTING, AND PARTICIPANTS: A retrospective analysis was performed in an academic tertiary care center. Participants included 14 younger adults (<65 years) and 15 older adults (≥65 years) who underwent revision cochlear implantation. INTERVENTION: Revision cochlear implantation. MAIN OUTCOMES AND MEASURES: Speech perception performance, as measured with consonant-nucleus-consonant [CNC] words in quiet, at the best prerevision interval as well as the 3- and 6-month postrevision intervals were compared between the 2 cohorts. The CNC word test consists of 10 lists of 50 phonemically balanced monosyllabic words, scored with a range of 0% to 100% correct. RESULTS: Both cohorts experienced a restoration in speech perception scores after revision cochlear implantation compared with their best performance before the revision (mean [SD] CNC word test scores for the younger cohort: 43.9% [25.6%] before revision and 47.7% [21.3%] at 3 months and 47.6% [19.8%] at 6 months after revision; for the older cohort: 36.3% [19.1%] before revision and 35.3% [17.2%] at 3 months and 39.9% [16.3%] at 6 months after revision; F2,54= 0.93; P = .40). There was no interaction between age at revision surgery and speech perception performance at each assessment interval (F2,54= 0.51; P = .60). CONCLUSIONS AND RELEVANCE: In this study, age at revision cochlear implantation was not related to postrevision speech perception performance. Advanced age should not be considered a contraindication to revision cochlear implantation.

Influence of cochlear implant insertion depth on performance: a prospective randomized trial.

OBJECTIVE: The purpose of the present study was to assess the influence of electrode insertion length on cochlear implant (CI) performance. STUDY DESIGN: Prospective randomized allocation of CI patients to receive either a standard (26.4 mm)- or medium (20.9 mm)-length electrode array. The processing strategy and electrode insertion number were held constant. The postoperative testing audiologist was blinded to the map details and array. SETTING: Tertiary referral center. PATIENTS: Thirteen adult CI candidates randomized to receive the standard- (n = 7) or medium-length (n = 6) electrode array. INTERVENTION(S): Unilateral CI using standard- or medium-length array from the same implant system. MAIN OUTCOME MEASURES(S): Speech perception was assessed with HINT sentences in quiet and steady-state noise (SNR, +10) and CNC words in quiet at defined intervals. Quality of life was assessed using the Hearing Device Satisfaction Survey and the Abbreviated Profile of Hearing Aid Benefit (APHAB). Music perception was assessed using the Musical Sounds In Cochlear implants (MuSIC) test. Postoperative electrode insertion angle was assessed using reconstructed computed tomographic images. RESULTS: Interim analysis necessitated discontinuation of subject enrollment by the institutional review board. There was a trend (p = 0.07) for improved speech perception performance among standard array patients. This difference was significant when the standard array group was increased retrospectively. Quality of life and music perception differences were not apparent between groups. CONCLUSION: Longer electrode insertions (and greater insertion angles) appear to offer better speech perception performance in the early postactivation period when using the same implant system.

Round window stimulation for conductive and mixed hearing loss.

OBJECTIVE: Assess surgical complications, postoperative residual hearing, and speech perception outcomes of placement of a middle ear implant on the round window in conductive and mixed hearing loss cases. STUDY DESIGN: Single-subject, repeated-measures design where each subject served as his or her own control. SETTING: Tertiary referral medical systems. SUBJECTS: Eighteen subjects with either conductive or mixed hearing loss who could not benefit from conventional amplification were enrolled in a clinical trial investigating vibratory stimulation of the round window. INTERVENTION: The floating mass transducer (FMT) was positioned in the round window niche. MAIN OUTCOME MEASURES: Unaided residual hearing, and aided sound field thresholds and speech perception abilities were evaluated preoperatively, and at 1, 3, 6, and 10 months post-activation of the external speech processor. RESULTS: Six subjects experienced complications that either required further medical management or resolved on their own. There was no difference in residual bone conduction thresholds or unaided word discrimination over time. All subjects experienced a significant improvement in aided speech perception abilities as compared to preoperative performance. CONCLUSION: Subjects with conductive and mixed hearing loss with placement of the FMT in the round window niche experienced improved sound field thresholds and speech perception, without compromising residual hearing thresholds. Vibratory stimulation of the round window via a middle ear implant may be an appropriate treatment option for patients with conductive and mixed hearing loss. Additional research is needed on the preferred placement of the FMT, improvement of functional gain, and methods to limit postoperative complications and need for revision surgery.

Effects of hearing aid settings for electric-acoustic stimulation.

BACKGROUND: Cochlear implant (CI) recipients with postoperative hearing preservation may utilize an ipsilateral bimodal listening condition known as electric-acoustic stimulation (EAS). Studies on EAS have reported significant improvements in speech perception abilities over CI-alone listening conditions. Adjustments to the hearing aid (HA) settings to match prescription targets routinely used in the programming of conventional amplification may provide additional gains in speech perception abilities. PURPOSE: Investigate the difference in users' speech perception scores when listening with the recommended HA settings for EAS patients versus HA settings adjusted to match National Acoustic Laboratories' nonlinear fitting procedure version 1 (NAL-NL1) targets. RESEARCH DESIGN: Prospective analysis of the influence of HA settings. STUDY SAMPLE: Nine EAS recipients with greater than 12 mo of listening experience with the DUET speech processor. INTERVENTION: Subjects were tested in the EAS listening condition with two different HA setting configurations. Speech perception materials included consonant-nucleus-consonant (CNC) words in quiet, AzBio sentences in 10-talker speech babble at a signal-to-noise ratio (SNR) of +10, and the Bamford-Kowal-Bench sentences in noise (BKB-SIN) test. DATA COLLECTION AND ANALYSIS: The speech perception performance on each test measure was compared between the two HA configurations. RESULTS: Subjects experienced a significant improvement in speech perception abilities with the HA settings adjusted to match NAL-NL1 targets over the recommended HA settings. CONCLUSIONS: EAS subjects have been shown to experience improvements in speech perception abilities when listening to ipsilateral combined stimulation. This population's abilities may be underestimated with current HA settings. Tailoring the HA output to the patient's individual hearing loss offers improved outcomes on speech perception measures.

Cochleostomy versus round window insertions: influence on functional outcomes in electric-acoustic stimulation of the auditory system.

OBJECTIVE: To assess the potential influence of 2 different surgical access routes to scala tympani for hearing preservation cochlear implantation on outcomes. STUDY DESIGN: Retrospective review. SETTING: Tertiary care academic center. PATIENTS: Twenty adult subjects participating in a prospective clinical trial on electric-acoustic stimulation. Subjects underwent cochlear implantation with attempted hearing preservation and subsequent ipsilateral electric-acoustic stimulation of the auditory system. INTERVENTIONS: Eight subjects (40%) were implanted using a round window-related cochleostomy and 12 subjects (60%) via a round window approach. MAIN OUTCOME MEASURES: Postoperative acoustic hearing preservation and speech perception measures were obtained at defined intervals and compared for both groups with and without the use of the external speech processor. RESULTS: The data demonstrate no statistically significant differences in postoperative outcomes for both preservation of residual hearing and unaided and aided speech perception between the cochleostomy and round window groups. CONCLUSION: The results of this investigation suggest that hearing preservation cochlear implantation can be performed either via a round window-related cochleostomy as well as via the round window membrane itself with similar outcomes in terms of both hearing preservation rates as well as speech perception measures.

Hearing preservation and speech perception outcomes with electric-acoustic stimulation after 12 months of listening experience.

OBJECTIVES/HYPOTHESIS: To report on single-center data of an FDA-approved clinical trial on the objective benefits of cochlear implantation and subsequent ipsilateral Electric-Acoustic Stimulation (EAS). STUDY DESIGN: Single-center data from a prospective, multicenter clinical trial. METHODS: Eighteen subjects completed the 12-month EAS evaluation and were included in this evaluation. Each patient underwent cochlear implantation using a standardized hearing preservation approach. Both hearing preservation and speech perception abilities were evaluated at various intervals. Speech testing included performance measures obtained in quiet (CNC words) and noise (adaptive CUNY protocol) in three listening conditions: hearing aid (HA) alone, cochlear implant (CI) only, and combined ipsilateral EAS. RESULTS: Various levels of hearing preservation were achieved with cochleostomy and round-window surgical approaches in 17 of the 18 subjects. Mean CNC word scores at the 12-month interval were 14.9 ± 12.1, 45.3 ± 15.4, and 70.7 ± 11.7% correct in the HA only, CI only, and EAS conditions, respectively. Average CUNY scores at 0 dB SNR were 14.6 ± 17.2, 47.1 ± 22.1, and 72.2 ± 21.5 for the three test conditions obtained after 12 months. CONCLUSIONS: Data obtained during this clinical trial correlate well with previous reports. Hearing preservation appears successful in a high number of subjects, and combined EAS offers excellent speech perception abilities in quiet and in noise. LEVEL OF EVIDENCE: 4.

Long-term speech perception in elderly cochlear implant users.

IMPORTANCE: A review of a test battery presented in both quiet and noise may clarify what the progression of speech perception abilities is in older adult cochlear implant users and whether the performance declines with advancing age. OBJECTIVE: To examine whether older adults (≥65 years) with cochlear implants maintain stable speech perception performance after at least 10 years of listening experience with an external speech processor. DESIGN AND SETTING: Retrospective analysis performed in an academic tertiary care center. PARTICIPANTS: Fourteen older adult cochlear implant recipients with at least 10 years of listening experience. MAIN OUTCOME MEASURES: Speech perception outcomes as measured with Consonant-Nucleus-Consonant words in quiet and Hearing in Noise Test sentences in quiet and steady-state noise were analyzed retrospectively at the 6-month and 1-, 5-, and 10-year postoperative follow-up intervals. RESULTS: Consonant-Nucleus-Consonant word scores remained stable between 6 months and 1 year of listening experience, improved significantly (P < .001) between 1 year and 5 years, and remained stable between 5 years and 10 years. Hearing in Noise Test sentence scores in quiet and noise showed a similar pattern, with stability in performance between the 6-month to 1-year and 5-year to 10-year follow-up intervals, and significantly improved performance (P = .04) between the 1-year and 5-year follow-up intervals. CONCLUSIONS AND RELEVANCE: On average, patients who undergo cochlear implantation at age 65 years or older do not experience a decline in speech perception performance with extended listening experience and may potentially continue to see improvements beyond the 1-year follow-up interval.

Is electric acoustic stimulation better than conventional cochlear implantation for speech perception in quiet?

OBJECTIVE: To assess whether combined electric acoustic stimulation (EAS) provides a significant hearing-in-quiet advantage over ipsilateral electrical stimulation alone, ipsilateral acoustic stimulation alone, or full-length cochlear implantation without preserved hearing. SETTING: Tertiary care academic referral center. PATIENTS: Two matched groups of cochlear implant (CI) patients that were implanted with either an EAS or full-length device and use similar speech processing strategies. INTERVENTION: EAS cochlear implantation and hearing preservation (n = 10, EAS group) or conventional CI (n = 10, conventional CI group) without hearing preservation. MAIN OUTCOME MEASURES: Status of residual hearing and speech perception data in quiet at 3 and 6 months after fitting. RESULTS: Preoperatively, the mean aided Consonant Nucleus Consonant Word Test word score was 24.2 +/- 8.3% for the EAS group and 20.7 +/- 11.36% for the conventional CI group (p = 0.14). In the conventional CI group, hearing was not preserved after surgery in any subject, whereas 9 of the 10 subjects in the EAS group had hearing preservation. Mean CNC word scores at 6 months after activation using electrical stimulation alone were 50.3 +/- 11.53% in the EAS group and 53.8 +/- 17.32% in the conventional CI group (p = 0.81). Between-condition comparisons among the EAS subjects revealed that combined stimulation was significantly better than either the electrical or acoustic stimulation condition alone (p < 0.05). When compared with the conventional CI group, combined stimulation in EAS subjects was again superior (p < 0.05). CONCLUSION: Limited length CI with ipsilateral hearing preservation provides comparable speech perception performance results to conventional CI when electric stimulation alone is used. The addition of ipsilateral acoustic stimulation in ears with preserved residual hearing provides an additional benefit over electrical stimulation alone.