Consonant-Nucleus-Consonant Word Scores Research Articles

Peripheral Neural Synchrony in Postlingually Deafened Adult Cochlear Implant Users.

This paper reports a noninvasive method for quantifying neural synchrony in the cochlear nerve (i.e., peripheral neural synchrony) in cochlear implant (CI) users, which allows for evaluating this physiological phenomenon in human CI users for the first time in the literature. In addition, this study assessed how peripheral neural synchrony was correlated with temporal resolution acuity and speech perception outcomes measured in quiet and in noise in postlingually deafened adult CI users. It tested the hypothesis that peripheral neural synchrony was an important factor for temporal resolution acuity and speech perception outcomes in noise in postlingually deafened adult CI users. Study participants included 24 postlingually deafened adult CI users with a Cochlear™ Nucleus® device. Three study participants were implanted bilaterally, and each ear was tested separately. For each of the 27 implanted ears tested in this study, 400 sweeps of the electrically evoked compound action potential (eCAP) were measured at four electrode locations across the electrode array. Peripheral neural synchrony was quantified at each electrode location using the phase-locking value (PLV), which is a measure of trial-by-trial phase coherence among eCAP sweeps/trials. Temporal resolution acuity was evaluated by measuring the within-channel gap detection threshold (GDT) using a three-alternative, forced-choice procedure in a subgroup of 20 participants (23 implanted ears). For each ear tested in these participants, GDTs were measured at two electrode locations with a large difference in PLVs. For 26 implanted ears tested in 23 participants, speech perception performance was evaluated using consonant-nucleus-consonant (CNC) word lists presented in quiet and in noise at signal to noise ratios (SNRs) of +10 and +5 dB. Linear Mixed effect Models were used to evaluate the effect of electrode location on the PLV and the effect of the PLV on GDT after controlling for the stimulation level effects. Pearson product-moment correlation tests were used to assess the correlations between PLVs, CNC word scores measured in different conditions, and the degree of noise effect on CNC word scores. There was a significant effect of electrode location on the PLV after controlling for the effect of stimulation level. There was a significant effect of the PLV on GDT after controlling for the effects of stimulation level, where higher PLVs (greater synchrony) led to lower GDTs (better temporal resolution acuity). PLVs were not significantly correlated with CNC word scores measured in any listening condition or the effect of competing background noise presented at an SNR of +10 dB on CNC word scores. In contrast, there was a significant negative correlation between the PLV and the degree of noise effect on CNC word scores for a competing background noise presented at an SNR of +5 dB, where higher PLVs (greater synchrony) correlated with smaller noise effects on CNC word scores. This newly developed method can be used to assess peripheral neural synchrony in CI users, a physiological phenomenon that has not been systematically evaluated in electrical hearing. Poorer peripheral neural synchrony leads to lower temporal resolution acuity and is correlated with a larger detrimental effect of competing background noise presented at an SNR of 5 dB on speech perception performance in postlingually deafened adult CI users.

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

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. 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. 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. 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.

Cochlear Implant Adult Speech Perception Outcomes: Seniors Have Similar Good Outcomes.

The primary aim was to analyze the speech perception outcomes of patients with cochlear implants 65 years and older, compared with those younger than 65 years. The secondary aim was to analyze if preoperative hearing levels, severe compared with profound, had an effect on speech perception outcomes in senior citizens. Retrospective case review of 785 patients, between 2009 and 2016. A large cochlear implant program. Cochlear implant adult recipients younger than 65 years and 65 years and older at the time of surgery. Therapeutic-cochlear implant. Speech perception outcomes, using City University of New York (CUNY) sentences and Consonant-Nucleus-Consonant (CNC) words. Outcomes were measured preoperatively and postoperatively at 3, 6and 12 months for cohorts younger than 65 years and 65 years and older. Adult recipients younger than 65 years compared with those 65 years and older had comparable outcomes for CUNY sentence scores outcomes ( p = 0.11) and CNC word scores ( p = 0.69). The preoperative four-frequency average severe hearing loss (HL) cohort was significantly better compared with the profound HL cohort, for both the CUNY sentence scores ( p < 0.001) and CNC word scores ( p < 0.0001). The four-frequency average severe HL cohort had better outcomes irrespective of age. Senior citizens have similarly good speech perception outcomes as adults younger than 65 years. Those with preoperative severe HL have better outcomes than profound loss. These finds are reassuring and can be used when counseling older cochlear implant candidates.

Slim Modiolar Electrode Placement in Candidates for Electroacoustic Stimulation.

To determine rates of hearing preservation and performance in patients who met candidacy for electroacoustic stimulation (EAS) and were implanted with a slim modiolar electrode (CI532 or CI632). Adult patients meeting Food and Drug Administration criteria for electroacoustic stimulation (preoperative low-frequency pure-tone average [LFPTA] less than 60 dB at 125, 250, and 500 Hz and monosyllabic word scores between 10% and 60% in the ear to be implanted), who received a slim modiolar electrode were included. Main outcome measures included rates of hearing preservation, defined as a LFPTA ≤80 dB at 125, 250, and 500 Hz, as well as postoperative low-frequency pure-tone threshold shifts, consonant-Nucleus-Consonant (CNC) word scores and AzBio sentences in noise scores. Forty-six patients met inclusion criteria during a 4-year period. Mean (standard deviation) preoperative LFPTA was 34.5 (13.0) dB, and 71.7% had preserved hearing at initial activation. The mean LFPTA shift in patients who preserved hearing at initial activation was 19.7 (14.6) dB, compared with 62.6 (17.7) dB in patients who did not preserve hearing as per our definition. Perioperative steroid use was not different in patients with and without preserved hearing (X 2 (1, N = 46) = 0.19, p = .67, V = 0.06). One year after surgery, 57% of patients had a decline in LFPTA >80 dB and were no longer considered candidates for EAS, with 34.7% still retaining low-frequency thresholds ≤80 dB. CNC word scores at 1 year were 69.9% and 61.4% among individuals with and without preserved low-frequency hearing respectively, measured in their CI ear alone, in their regular listening condition of EAS or electric only ( t (32) = 1.13, p = 0.27, d = 0.39, 95% CI = -6.51, 22.86). Device use time did not differ between groups. Among adults with preserved residual hearing at 1 year (n = 16), 44% used EAS, although there was no significant difference in performance between EAS users and nonusers with preserved hearing. Loss of residual hearing over time did not result in a decline in speech perception performance. The present study demonstrated favorable early rates of hearing preservation with a slim modiolar array. Performance was not significantly different in individuals with and without preserved low-frequency acoustic hearing, independent of EAS use. Compared with reports of short electrode use, the loss of residual hearing in patients implanted with this array did not impact speech perception performance.

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.

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. 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. 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. 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.

Postlingually Deafened Adult Cochlear Implant Users With Prolonged Recovery From Neural Adaptation at the Level of the Auditory Nerve Tend to Have Poorer Speech Perception Performance.

This study investigated the effects of two temporal response properties of the auditory nerve (i.e., neural adaptation and recovery from neural adaptation) on speech perception performance in postlingually deafened adult cochlear implant (CI) users. Study participants included 18 postlingually deafened adults who were Cochlear Nucleus device users with a full electrode array insertion in the test ear(s). Neural adaptation and adaptation recovery of the auditory nerve (AN) were evaluated using electrophysiological measures of the electrically evoked compound action potential (eCAP). The amount of neural adaptation was quantified by the adaptation index within three time windows: 0 to 8.89 (window 1), 44.44 to 50.00 (window 2), and 94.44 to 100.00 ms (window 3). The speed of neural adaptation was estimated using a two-parameter power law function. To evaluate adaptation recovery of the AN, eCAPs to the last pulse of the 100-ms pulse train were recorded at masker-probe-intervals ranging from 1.054 to 256 ms in logarithmic steps. The amount of adaptation recovery was quantified by the adaptation recovery ratio. The time-constant of adaptation recovery was estimated using an exponential function with up to three components. Speech perception performance was evaluated by measuring consonant-nucleus-consonant (CNC) word scores presented in quiet and in speech-shaped noise at a signal-to-noise ratio (SNR) of +10 dB. One-tailed Pearson Product Moment correlation tests were used (1) to assess the associations among parameters of neural adaptation and adaptation recovery and (2) to evaluate the strength of association between these parameters and CNC word scores measured in quiet and in noise. The contributions of different parameters quantifying neural adaptation and adaptation recovery on speech perception scores were evaluated using multivariable linear regression analyses. The Pearson Product Moment correlation coefficient demonstrated a moderate, negative correlation between the speed of adaptation recovery and CNC word scores measured in quiet and in noise. The speed of adaptation recovery accounted for 14.1% of variability in CNC word scores measured in quiet and 16.7% of variability in CNC word scores measured in noise. The correlation strengths between CNC word scores and the adaptation index, the adaptation recovery ratio and the speed of neural adaptation ranged from negligible to weak. The speed of adaptation recovery plays a more important role than other features of neural adaptation and adaptation recovery of the AN in speech perception in postlingually deafened adult CI users. Patients with prolonged adaptation recovery tend to show poorer speech perception performance.

Association of Self-Reported Coping Strategies With Speech Recognition Outcomes in Adult Cochlear Implant Users.

To characterize the degree to which individual coping strategies may influence speech perception after cochlear implantation. Retrospective cohort study. Tertiary referral center. Adult, postlingually deaf cochlear implant recipients. The Coping Orientation to Problems Experience inventory, a validated, multidimensional self-reported coping scale, was administered preoperatively. Speech perception was measured using consonant-nucleus-consonant (CNC) phoneme and word scores, AzBio sentence accuracy in quiet and noise, and Hearing in Noise Test sentences in quiet preoperatively and at 1, 3, and 6 months postoperatively. Quality of life was measured with the Hearing Implant Sound Quality Index and the Nijmegen Cochlear Implant Questionnaire. Thirty-six patients were included in this study. Mean age at surgery was 70.7 ± 11.4 years. Acceptance was associated with a decreased AzBio in noise score in the 6 months after CI (regression coefficient b = -0.05; 95% confidence interval [CI], -0.07 to -0.03; p < 0.01). Denial was associated with a decreased AzBio in quiet score (b = -0.05; 95% CI, -0.09 to -0.01; p < 0.05), whereas humor was associated with an increased AzBio in quiet score (b = 0.02; 95% CI, 0.01 to 0.04; p < 0.05). Humor was also associated with an increased Hearing in Noise Test score (b = 0.05; 95% CI, 0.02 to 0.07; p < 0.05). Denial was associated with decreased CNC word (b = -0.04; 95% CI, -0.06 to -0.02; p < 0.01) and phoneme (b = -0.04; 95% CI, -0.07 to -0.02; p < 0.01) scores, whereas substance use was associated with increased CNC word (b = 0.03; 95% CI, 0.01 to 0.05, p < 0.01) and phoneme (b = 0.04; 95% CI, 0.02 to 0.06; p < 0.01) scores. Scores on self-reported quality of life measures were not significantly correlated with coping strategies. A variety of adaptive and maladaptive coping strategies are used by postlingually deaf adult cochlear implant users. Denial and acceptance may be more predictive of poor speech performance, whereas humor and substance use may be more predictive of improved speech performance.

Cochlear Implantation Outcomes in Patients With Retrocochlear Pathology: A Systematic Review and Pooled Analysis.

To review the current literature regarding cochlear implantation in patients with retrocochlear pathologies and extract speech perception scores between 6 months and 1 year after surgery. PubMed/MEDLINE, Embase and Cochrane CENTRAL via Ovid, CINAHL Complete via Ebsco, and Web of Science. The review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Search strategies included keywords and subject headings to maximize retrieval and reflect cochlear implants and retrocochlear pathologies. Patients with previously resected vestibular schwannoma (VS) were excluded. There were 2,524 abstracts screened against inclusion criteria, and 53 studies were included, with individual data available for 171 adult patients. Pathologies included were either observed or irradiated VS (previously operated tumors were excluded) (n = 99, 57.9%), superficial siderosis (n = 39, 22.8%), neurosarcoidosis (n = 11, 6.4%), and previous central nervous system or skull base radiation (n = 22, 12.9%). Mean (standard deviation) postoperative consonant-nucleus-consonant (CNC) word scores were 45.4% (24.2) for observed VS, 44.4% (20.8) for irradiated VS, 43.6% (21.0) for superficial siderosis, 89.5% (3.0) for neurosarcoidosis, and 30.0% (30.2) in patients with previous central nervous system or skull base irradiation. Irradiated compared with observed VS had similar postoperative CNC word scores (effect size, 0.06; p = 0.71). Age, sex, maximal tumor dimension, and neurofibromatosis type 2 status did not significantly impact cochlear implant performance in patients with VS. Eighty-two percent of patients with reported device usage were daily users, and overall, 82% of cases benefitted from cochlear implantation. Cochlear implantation in patients with concomitant retrocochlear pathology generally results in improved speech discrimination scores sustained over time.

(Even Off-Label) Cochlear Implantation in Single-Sided Deafness and Asymmetric Hearing Loss Results in Measurable Objective and Subjective Benefit.

To quantify objective and subjective outcomes in cochlear implant (CI) recipients with asymmetric hearing loss, including single-sided deafness (SSD) whose candidacy was determined on an ear-specific basis when word recognition was 50% or less. Retrospective case review. Tertiary referral center. The effectiveness of CI in cases of SSD and asymmetric hearing loss (AHL) has been described in terms of tinnitus suppression, improved speech recognition in quiet and noise, enhanced localization ability, and improved quality of life. However, CI is not yet routinely offered as a top option or standard of care for these individuals. Recent Food and Drug Administration (FDA) labeling limits aided word recognition in the ear to be implanted to only 5% in cases of AHL/SSD, which is significantly poorer than 40 to 50%, which is often referenced in cases of bilateral hearing loss. Anecdotal experience suggests that patients with much better preoperative word recognition than 5% can benefit from CI. We conducted a retrospective chart review of all adult CI candidates, with one ear exhibiting consonant-nucleus-consonant (CNC) word recognition scores at least 50% and one ear not meeting CI candidacy (i.e., CNC word recognition >50%). Outcome variables of interest included word and sentence recognition and subjective handicap questionnaires (hearing, tinnitus, dizziness) and the Speech Spatial Qualities questionnaire. Statistically and clinically significant improvement in speech understanding (word, sentence, sentence in noise) was noted for both the SSD and AHL groups in the implanted ear. There were statistically and clinically significant subjective improvements noted for both groups on the Hearing Handicap Inventory, the Tinnitus Handicap Inventory, and the Speech Spatial Qualities questionnaire by 1 month after activation. There were no significant differences between the AHL and SSD groups on either objective or subjective measures of the implanted ear. Individual word understanding improved for the majority of recipients across both groups and is not dependent on meeting the FDA criteria of less than 5%. Cochlear implantation is a viable option with measurable objective and perceived benefits for recipients with preoperative aided CNC word scores exceeding current FDA labeling. There is no significant difference between the AHL and SSD groups, suggesting that candidacy and outcome expectations should be set based on the ear to be implanted alone, without regard for the ability of the better hearing ear.

TMPRSS3 expression is limited in spiral ganglion neurons: implication for successful cochlear implantation

BackgroundIt is well established that biallelic mutations in transmembrane protease, serine 3 (TMPRSS3) cause hearing loss. Currently, there is controversy regarding the audiological outcomes after cochlear implantation (CI) for TMPRSS3-associated...

Insertion Depth and Cochlear Implant Speech Recognition Outcomes: A Comparative Study of 28- and 31.5-mm Lateral Wall Arrays.

1) To compare speech recognition outcomes between cochlear implant (CI) recipients of 28- and 31.5-mm lateral wall electrode arrays, and 2) to characterize the relationship between angular insertion depth (AID) and speech recognition. Retrospective review. Tertiary academic referral center. Seventy-five adult CI recipients of fully inserted 28-mm (n = 28) or 31.5-mm (n = 47) lateral wall arrays listening with a CI-alone device. Cochlear implantation with postoperative computed tomography. Consonant-nucleus-consonant (CNC) word recognition assessed with the CI-alone at 12 months postactivation. The mean AID of the most apical electrode contact for the 31.5-mm array recipients was significantly deeper than the 28-mm array recipients (628° vs 571°, p < 0.001). Following 12 months of listening experience, mean CNC word scores were significantly better for recipients of 31.5-mm arrays compared with those implanted with 28-mm arrays (59.5% vs 48.3%, p = 0.004; Cohen's d = 0.70; 95% CI [0.22, 1.18]). There was a significant positive correlation between AID and CNC word scores (r = 0.372, p = 0.001), with a plateau in performance observed around 600°. Cochlear implant recipients implanted with a 31.5-mm array experienced better speech recognition than those with a 28-mm array at 12 months postactivation. Deeper insertion of a lateral wall array appears to confer speech recognition benefit up to ∼600°, with a plateau in performance observed thereafter. These data provide preliminary evidence of the insertion depth necessary to optimize speech recognition outcomes for lateral wall electrode arrays among CI-alone users.

A Novel Performance-Based Paradigm of Care for Cochlear Implant Follow-Up.

Utilize a multi-institutional outcomes database to determine expected performance for adult cochlear implant (CI) users. Estimate the percentage of patients who are high performers and achieve performance plateau. Retrospective database study. Outcomes from 9,448 implantations were mined to identify 804 adult, unilateral recipients who had one preoperative and at least one postoperative consonant-nucleus-consonant (CNC) word score. Results were examined to determine percent-correct CNC word recognition preoperatively and at 1, 3, 6, 12, and 24 months after activation. Outcomes from 318 similar patients who also had at least three postoperative CNC word scores were examined. Linear mixed-effects regression was used to examine CNC word performance over time. The time when each patient achieved maximum performance was recorded as a surrogate for time of performance plateau. Patients were assigned as candidates for less intense follow-up if they were high performers and achieved performance plateau. Among 804 patients with at least one postoperative score, CNC score improved at all time intervals. Average performance after the 3-month time interval was 47.2% to 51.5%, indicating a CNC ≥ 50% cutoff for high performers. Among 318 patients with at least three postoperative scores, performance improved from 1 to 3 (P=.001), 3 to 6 (P=.001), and 6 to 12 (P=.01) months. Scores from the 12- and 24-month intervals did not significantly differ (P=.09). By 12 months after activation, 59.7% of patients were considered candidates for less intense follow-up. Findings suggest that CNC ≥ 50% is a reasonable cutoff to separate high performers from low performers. Within 12 months after activation, 59.7% of patients were good candidates for less intense follow-up. 3 Laryngoscope, 132:S1-S10, 2022.

Further Evidence for the Expansion of Adult Cochlear Implant Candidacy Criteria.

1) To complete a follow-up investigation of postoperative outcomes for adult cochlear implant (CI) recipients scoring ≥30% Consonant-Nucleus-Consonant (CNC) preoperatively, and 2) to describe the postoperative performance trajectory for this group of higher performing patients. Retrospective chart review. Tertiary referral center. One hundred four (105 ears) postlingually deafened adults who scored ≥30% CNC word recognition in the ear to be implanted preoperatively. One hundred four subjects underwent cochlear implantation. Pre- and postoperative CNC word scores and AzBio sentences in quiet and noise in the ear to be implanted as well as the bilateral-aided condition pre-CI and at 1, 3, 6, and 12 months post-CI. Statistically significant improvement was demonstrated for CNC and AzBio sentences in quiet and noise for the CI alone and bilateral listening conditions. Most improvement was demonstrated by 6-months postoperatively (p < 0.001) with the exception of AzBio sentences in noise demonstrating improvement within 3 months (p < 0.001). For patients with preop CNC scores up to 40% (n = 57), all recipients demonstrated either equivocal (n = 17) or statistically significant improvement (n = 40) for CNC word recognition in the CI-alone condition and none demonstrated a significant decrement in the bilateral condition. For patients with preop CNC scores >40% (n = 47, 48 ears), 89.3% (42 patients) demonstrated either equivocal (n = 24, 50%) or statistically significant improvement (n = 19, 39.6%) for CNC word recognition in the CI-only condition and none demonstrated a significant decrement in the bilateral condition. CI candidates with preoperative CNC word scores higher than conventional CI recipients derive statistically significant benefit from cochlear implantation for both the CI ear and best-aided condition. These data provide further support for the expansion of adult CI candidacy up to at least 40% CNC word recognition preoperatively with consideration given to further expansion possibly up to 60%.

Delaying Cochlear Implantation Impacts Postoperative Speech Perception of Nontraditional Pediatric Candidates

Introduction: As pediatric cochlear implant (CI) candidacy expands, children with greater degrees of residual hearing are receiving CIs. These nontraditional candidates have audiometric thresholds that meet adult manufacturer labeling but are better than current pediatric guidelines allow. The purpose of this study was to determine the impact of delayed cochlear implantation on speech perception in nontraditional pediatric CI recipients. Methods: Pediatric CI recipients with a history of progressive hearing loss and a preoperative 4-frequency pure-tone average of ≤75 dB HL at the time of implantation were considered for this retrospective study. Preoperative serial audiograms and word recognition scores were reviewed, and a method was created to establish a date when each individual ear 1st met nontraditional candidacy. The length of time between the date of candidacy and implantation was calculated and defined as the “delay time.” A multiple linear regression investigated delay time, age at surgery, surgery type (1st vs. 2nd side), and array type as predictive factors of maximum postoperative Consonant-Nucleus-Consonant (CNC) word scores. A one-way ANCOVA was performed comparing the postoperative CNC scores between subjects grouped by delay time. Results: A significant regression was found (F(4, 38) = 5.167, p = 0.002, R² = 0.353). Both age at implantation (p = 0.023) and delay time (p = 0.002) predicted CNC word scores. Longer delay time was associated with poorer word recognition scores, while older age at implantation correlated with higher CNC word scores in this progressive hearing loss group. A significant difference was noted between subjects implanted with <1 year of delay and those with 3 or more years of delay (p = 0.003). All ears implanted within a year of candidacy achieved word recognition abilities that are generally accepted as above average (M = 84.91). Conclusion: CI candidacy for adults has evolved to allow for greater degrees of residual hearing, while audiometric guidelines for children have not changed since 2000. Our findings suggest that delay of cochlear implantation, even for children with significant levels of residual hearing, leads to poorer outcomes. Modified candidacy guidelines for children should be established to expedite referral to multidisciplinary CI teams and minimize delays in this population.

Relationship Between Electrocochleography, Angular Insertion Depth, and Cochlear Implant Speech Perception Outcomes.

Electrocochleography (ECochG), obtained before the insertion of a cochlear implant (CI) array, provides a measure of residual cochlear function that accounts for a substantial portion of variability in postoperative speech perception outcomes in adults. It is postulated that subsequent surgical factors represent independent sources of variance in outcomes. Prior work has demonstrated a positive correlation between angular insertion depth (AID) of straight arrays and speech perception under the CI-alone condition, with an inverse relationship observed for precurved arrays. The purpose of the present study was to determine the combined effects of ECochG, AID, and array design on speech perception outcomes. Participants were 50 postlingually deafened adult CI recipients who received one of three straight arrays (MED-EL Flex24, MED-EL Flex28, and MED-EL Standard) and two precurved arrays (Cochlear Contour Advance and Advanced Bionics HiFocus Mid-Scala). Residual cochlear function was determined by the intraoperative ECochG total response (TR) measured before array insertion, which is the sum of magnitudes of spectral components in response to tones of different stimulus frequencies across the speech spectrum. The AID was then determined with postoperative imaging. Multiple linear regression was used to predict consonant-nucleus-consonant (CNC) word recognition in the CI-alone condition at 6 months postactivation based on AID, TR, and array design. Forty-one participants received a straight array and nine received a precurved array. The AID of the most apical electrode contact ranged from 341° to 696°. The TR measured by ECochG accounted for 43% of variance in speech perception outcomes (p < 0.001). A regression model predicting CNC word scores with the TR tended to underestimate the performance for precurved arrays and deeply inserted straight arrays, and to overestimate the performance for straight arrays with shallower insertions. When combined in a multivariate linear regression, the TR, AID, and array design accounted for 72% of variability in speech perception outcomes (p < 0.001). A model of speech perception outcomes that incorporates TR, AID, and array design represents an improvement over a model based on TR alone. The success of this model shows that peripheral factors including cochlear health and electrode placement may play a predominant role in speech perception with CIs.

Electric-Acoustic Stimulation Outcomes in Children.

This study investigates outcomes in children fit with electric-acoustic stimulation (EAS) and addresses three main questions: (1) Are outcomes with EAS superior to outcomes with conventional electric-only stimulation in children? (2) Do children with residual hearing benefit from EAS and conventional electric-only stimulation when compared with the preoperative hearing aid (HA) condition? (3) Can children with residual hearing derive benefit from EAS after several years of listening with conventional electric-only stimulation? Sixteen pediatric cochlear implant (CI) recipients between 4 and 16 years of age with an unaided low-frequency pure tone average of 75 dB HL in the implanted ear were included in two study arms. Arm 1 included new recipients, and Arm 2 included children with at least 1 year of CI experience. Using a within-subject design, participants were evaluated unilaterally with the Consonant-Nucleus-Consonant (CNC) word list in quiet and the Baby Bio at a +5 dB SNR using an EAS program and a conventional full electric (FE) program. Arm 1 participants' scores were also compared with preoperative scores. Speech perception outcomes were statistically higher with the EAS program than the FE program. For new recipients, scores were significantly higher with EAS than preoperative HA scores for both the CNC and Baby Bio in noise; however, after 6 months of device use, results in the FE condition were not significantly better than preoperative scores. Long-term FE users benefited from EAS over their FE programs based on CNC word scores. Whether newly implanted or long-term CI users, children with residual hearing after CI surgery can benefit from EAS. Cochlear implantation with EAS fitting is a viable option for children with HAs who have residual hearing but have insufficient access to high-frequency sounds and poor speech perception.

The Effect of Hearing Aid Bandwidth and Configuration of Hearing Loss on Bimodal Speech Recognition in Cochlear Implant Users.

(1) To determine the effect of hearing aid (HA) bandwidth on bimodal speech perception in a group of unilateral cochlear implant (CI) patients with diverse degrees and configurations of hearing loss in the nonimplanted ear, (2) to determine whether there are demographic and audiometric characteristics that would help to determine the appropriate HA bandwidth for a bimodal patient. Participants were 33 experienced bimodal device users with postlingual hearing loss. Twenty three of them had better speech perception with the CI than the HA (CI>HA group) and 10 had better speech perception with the HA than the CI (HA>CI group). Word recognition in sentences (AzBio sentences at +10 dB signal to noise ratio presented at 0° azimuth) and in isolation [CNC (consonant-nucleus-consonant) words] was measured in unimodal conditions [CI alone or HAWB, which indicates HA alone in the wideband (WB) condition] and in bimodal conditions (BMWB, BM2k, BM1k, and BM500) as the bandwidth of an actual HA was reduced from WB to 2 kHz, 1 kHz, and 500 Hz. Linear mixed-effect modeling was used to quantify the relationship between speech recognition and listening condition and to assess how audiometric or demographic covariates might influence this relationship in each group. For the CI>HA group, AzBio scores were significantly higher (on average) in all bimodal conditions than in the best unimodal condition (CI alone) and were highest at the BMWB condition. For CNC scores, on the other hand, there was no significant improvement over the CI-alone condition in any of the bimodal conditions. The opposite pattern was observed in the HA>CI group. CNC word scores were significantly higher in the BM2k and BMWB conditions than in the best unimodal condition (HAWB), but none of the bimodal conditions were significantly better than the best unimodal condition for AzBio sentences (and some of the restricted bandwidth conditions were actually worse). Demographic covariates did not interact significantly with bimodal outcomes, but some of the audiometric variables did. For CI>HA participants with a flatter audiometric configuration and better mid-frequency hearing, bimodal AzBio scores were significantly higher than the CI-alone score with the WB setting (BMWB) but not with other bandwidths. In contrast, CI>HA participants with more steeply sloping hearing loss and poorer mid-frequency thresholds (≥82.5 dB) had significantly higher bimodal AzBio scores in all bimodal conditions, and the BMWB did not differ significantly from the restricted bandwidth conditions. HA>CI participants with mild low-frequency hearing loss showed the highest levels of bimodal improvement over the best unimodal condition on CNC words. They were also less affected by HA bandwidth reduction compared with HA>CI participants with poorer low-frequency thresholds. The pattern of bimodal performance as a function of the HA bandwidth was found to be consistent with the degree and configuration of hearing loss for both patients with CI>HA performance and for those with HA>CI performance. Our results support fitting the HA for all bimodal patients with the widest bandwidth consistent with effective audibility.

The Compound Action Potential in Subjects Receiving a Cochlear Implant.

The compound action potential (CAP) is a purely neural component of the cochlea's response to sound, and may provide information regarding the existing neural substrate in cochlear implant (CI) subjects that can help account for variance in speech perception outcomes. Measurement of the "total response" (TR), or sum of the magnitudes of spectral components in the ongoing responses to tone bursts across frequencies, has been shown to account for 40 to 50% of variance in speech perception outcomes. The ongoing response is composed of both hair cell and neural components. This correlation may be improved with the addition of the CAP. Intraoperative round window electrocochleography (ECochG) was performed in adult and pediatric CI subjects (n = 238). Stimuli were tones of different frequencies (250 Hz-4 kHz) at 90 dB nHL. The CAP was assessed in two ways, as an amplitude and with a scaling factor derived from a function fitted to the response. The results were correlated with consonant-nucleus-consonant (CNC) word scores at 6 months post-implantation (n = 51). Only about half of the subjects had a measurable CAP at any frequency. The CNC word scores correlated weakly with both amplitude (r = 0.20, p < 0.001) and scaling factor (r = 0.25, p < 0.01). In contrast, the TR alone accounted for 43% of the variance, and addition of either CAP measurement in multiple regression did not account for additional variance. The underlying pathology in CI patients causes the CAP to be often absent and highly variable when present. The TR is a better predictor of speech perception outcomes than the CAP.

Long-Term Outcome Data in Patients following One Year's Use of a Fully Implantable Active Middle Ear Implant

This study examined the safety and efficacy of a fully implantable active middle ear (AMEI) system. Outcome measures assessed AMEI performance compared with an optimally fitted conventional hearing aid (CHA). Fifty adults with stable, symmetric moderate-to-severe sensorineural hearing loss were implanted at 9 ambulatory settings. Consonant-Nucleus-Consonant (CNC) words, Bamford-Kowel-Bench Speech in Noise test (BKB-SIN), Abbreviated Profile of Hearing Aid Benefit (APHAB), and unaided hearing thresholds in the implanted ear were compared to baseline measures obtained using a personal CHA. Changes in thresholds were observed from pre- to 12-month postoperative assessments. CNC word scores decreased (within 10%), and the BKB-SIN showed no change from pre- to 12-month postoperative time points. The APHAB revealed improvement. Findings suggest no difference in performance between an appropriately fit CHA and the AMEI at 12 months. This study indicates AMEIs have the potential to help individuals who choose not to use CHAs.

Outcomes of Cochlear Implantation in Adults with Asymmetric Hearing Loss

To analyze speech recognition outcomes in adult cochlear implant recipients who have asymmetric sensorineural hearing loss between the two ears. Retrospective cohort study of 35 adults with asymmetric hearing loss. Preoperative unaided pure-tone averages (PTA), and pre- and post-op (6 and 12 mo) aided Consonant Nucleus Consonant (CNC) words and sentence recognition scores were obtained for ears in isolation (opposite ear plugged). Patients were categorized according to the PTA of the implanted and contralateral ears as (a) moderate-severe, (b) moderate-profound, and (c) severe-profound. A single tertiary care center. Adults with asymmetric PTA implanted unilaterally at our institution. Cochlear implantation with devices approved by the U.S. Food and Drug Administration. Post-implantation word, phoneme, and sentence recognition in the cochlear implant alone testing condition. Patients who were implanted in the worse-hearing ear (n = 21) performed significantly better on CNC words and phonemes at 6 and 12 months than patients who were implanted in the better-hearing ear (n = 14). Patients with the worse ear implanted also obtained 6 to 12% higher sentence recognition scores than the group received an implant in their better ear, although this difference is not statistically significant (p = 0.06 at 6 mo; p = 0.1 at 12 mo). Patients with asymmetrical hearing loss who were implanted in the worse-hearing ear achieved 15% greater CNC word scores and 6 to 12% greater sentence scores than patients implanted in the better-hearing ear in the first year after surgery. Our results provide further support for clinicians to use caution if considering implanting the better-hearing ear in patients with asymmetric hearing loss.