Search

Background: Cochlear implantation is an effective auditory rehabilitation strategy for those with profound hearing loss, including those with residual low frequency hearing through use of hybrid cochlear implantation techniques. Post-mortem studies demonstrate the nearly ubiquitous presence of intracochlear fibrosis and neo-ossification following cochlear implantation. Current evidence suggests post-implantation intracochlear fibrosis is associated with delayed loss of residual acoustic hearing in hybrid cochlear implant (CI) recipients and may also negatively influence outcomes in traditional CI recipients. This study examined the contributions of surgical trauma, foreign body response and electric stimulation to intracochlear fibrosis and the innate immune response to cochlear implantation and the hierarchy of these contributions., Methods: Normal hearing CX3CR1 +/GFP mice underwent either round window opening (sham), acute CI insertion or chronic CI insertion with no, low- or high-level electric stimulation. Electric stimulation levels were based on neural response telemetry (NRT), beginning post-operative day 7 for 5 h per day. Subjects (n=3 per timepoint) were sacrificed at 4 h, 1,4,7,8,11,14 and 21 days. An unoperated group (n=3) served as controls. Cochleae were harvested at each time-point and prepared for immunohistochemistry with confocal imaging. The images were analyzed to obtain CX3CR1+ macrophage cell number and density in the lateral wall (LW), scala tympani (ST) and Rosenthal's canal (RC)., Results: A ST peri-implant cellular infiltrate and fibrosis occurred exclusively in the chronically implanted groups starting on day 7 with a concurrent infiltration of CX3CR1+ macrophages not seen in the other groups. CX3CR1+ macrophage infiltration was seen in the LW and RC in all experimental groups within the first week, being most prominent in the 3 chronically implanted groups during the second and third week., Conclusions: The cochlear immune response was most prominent in the presence of chronic cochlear implantation, regardless of electric stimulation level. Further, the development of intracochlear ST fibrosis was dependent on the presence of the indwelling CI foreign body. An innate immune response was evoked by surgical trauma alone (sham and acute CI groups) to a lesser degree. These data suggest that cochlear inflammation and intrascalar fibrosis after cochlear implantation are largely dependent on the presence of a chronic indwelling foreign body and are not critically dependent on electrical stimulation. Also, these data support a role for surgical trauma in inciting the initial innate immune response., Competing Interests: Declaration of Competing Interest This research was partially funded by and performed in collaboration with Cochlear Americas as research partners, with no financial or non-financial influence dependent on the outcome or reporting and sharing of data. MRH is a co-founder and Chief Medical Officer of iotaMotion Inc with equity interest. JRK is employed by Cochlear Limited., (Copyright © 2022 The Author(s). Published by Elsevier B.V. All rights reserved.)

Objectives/hypothesis: To determine the timing of acoustic hearing changes among hearing preservation Cochlear implant (CI) recipients. To determine differences in hearing outcomes based on device type and demographic factors. To determine if there is a relationship between the extent of early hearing loss after CI and the subsequent rate of continued hearing loss., Study Design: Prospective, single subject study., Methods: Two hundred and eleven subjects who received a hearing preservation CI were included in the study-80 Nucleus Hybrid L24 (Cochlear), 47 422/522 (Cochlear), 24 S8 (Cochlear), 14 S12 (Cochlear), 6 SRW (Cochlear), 21 SLIM J (Advanced Bionics), and 19 Flex (Med-EL). Of these, 127 were included in the subsequent analyses. Audiometric thresholds (low frequency pure-tone-averages) were collected and compared pre and postoperatively., Results: Long-term hearing preservation rates were 65% (52/80) for L24, 83% (20/24) for S8, 79% (11/14) for S12, 83% (5/6) for SRW, 54% (25/47) for 422/522, 91% (21/23) for SLIM J, and 84% (16/19) for Flex. Hearing loss was not related to device type (P = .9105) or gender (P = .2169). Older subjects (age ≥65) had worse hearing outcomes than younger subjects after initial device activation (age <65, P = .0262). There was no significant difference in rate of hearing loss over time between older and younger patients (P = .0938). Initial postoperative hearing loss was not associated with the rate of long-term hearing loss., Conclusions: Long-term low frequency hearing preservation is possible for CI recipients and is not associated with gender or device type. Rate of hearing loss over time is not dependent on patient age. Early hearing loss after CI does not predict the rate of long-term hearing loss., Level of Evidence: 3 Laryngoscope, 132:2036-2043, 2022., (© 2021 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Ecological momentary assessment (EMA) often places high physical and mental burden on research participants compared with retrospective self-reports. The high burden could result in noncompliance with the EMA sampling scheme protocol. It has been a concern that certain types of participants could be more likely to have low compliance, such as those who have severe hearing loss and poor speech recognition performance, are employed, are not familiar with technologies used to implement EMA (e.g., smartphones), and have poorer cognitive abilities. Noncompliance dependent on personal characteristics could negatively impact the generalizability of EMA research., Purpose: This article aims to determine personal characteristics associated with EMA compliance in a group of adult cochlear implant (CI) candidates and users., Research Design: An observational study., Study Sample: Fifty-eight adults who were either scheduled to received CIs or were experienced CI users completed the study., Data Collection and Analysis: Participants conducted smartphone-based EMA designed to assess an individual's daily auditory ecology for 1 week. EMA compliance was quantified using two metrics: the number of completed surveys and the response rate to the notification delivered by the EMA app. Personal characteristics (i.e., predictors) included age, gender, CI status (candidate or user), employment status (employed or not employed), smartphone ownership, speech recognition performance, social network size, level of depressive symptoms, and neurocognitive abilities. A word recognition test, questionnaires, and a test battery of neurocognitive assessments were used to measure the predictors. We used negative binomial regression and logistic mixed models to determine the factors associated with the number of completed surveys and the response rate, respectively. We hypothesized that, for example, employed participants with poorer speech recognition performance would have lower compliance., Results: Contrary to the hypothesis, word recognition score was negatively associated with the number of completed surveys ( p  = 0.022). Holding all other variables constant, a 10-point (i.e., 10%) word recognition score decrease was associated with an 11% increase in the number of completed surveys. For the response rate, employment status was the only significant predictor ( p  < 0.0001). Consistent with our hypothesis, the odds of responding to EMA notifications for those who are not employed are 82% higher than the odds for those who are employed. No other studied personal characteristic was associated with compliance., Conclusion: For CI candidates and users, EMA compliance could be affected by personal characteristics such as speech recognition performance and employment status. Because (1) participants with poorer speech recognition performance do not necessarily have lower compliance and (2) most personal characteristics investigated in the present study (e.g., age, gender, smartphone ownership, and neurocognitive abilities) do not predict compliance, a wide range of participants could successfully conduct smartphone-based EMA., Competing Interests: None declared., (American Academy of Audiology. This article is published by Thieme.)

Objectives/hypothesis: The use of a short 10-mm/10-electrode cochlear implant to preserve low-frequency residual hearing was investigated. This report describes the 12-month outcomes of this multicenter clinical trial., Study Design: Single-subject design., Methods: Twenty-eight subjects with low-frequency hearing at or better than 60 dB HL at 500 Hz and severe high-frequency hearing loss were implanted with a Nucleus Hybrid S12 implant in their poorer ear. Speech perception in quiet using Consonant-Nucleus-Consonant (CNC) words and sentences in noise using AzBio sentences was collected pre- and postoperatively at 3, 6, and 12 months. Subjective reporting using the Speech, Spatial, and Qualities of Hearing Scale (SSQ) questionnaire was also collected pre- and postoperatively., Results: Functional hearing preservation was accomplished in 96% of subjects. At 3 and 6 months, 86% of the 28 subjects had maintained functional hearing. By 12 months, 23 out of 27 subjects (85%) had maintained functional hearing (one subject with functional hearing at 6 months withdrew from the study prior to the 12-month visit). Speech perception results demonstrated that 81% of the participants on CNC words and 77% with AzBio sentences in noise had significant improvements using their everyday listening condition at 12 months compared to preoperative performance with bilateral hearing aids. Furthermore, preoperative to 12 months postoperative subjective ratings showed significant improvements for the SSQ., Conclusions: This study demonstrates that a high degree of hearing preservation enabling acoustic-electric hearing and improvement in speech understanding in quiet and in noise can be accomplished using a short-electrode 10-mm cochlear implant., Level of Evidence: 2c Laryngoscope, 130:E548-E558, 2020., (© 2020 The American Laryngological, Rhinological and Otological Society, Inc.)

Objective: Few studies have investigated the stability of residual hearing and speech perception outcomes in individuals who were implanted with a shorter electrode device., Study Design: Longitudinal, single-subject design., Methods: Fifty subjects who received a Nucleus Hybrid (Cochlear, Sydney, Australia) short electrode cochlear implant (CI) and had a minimum of 2 years (and up to 15 years) of postoperative longitudinal experience were included in this study. Twenty-three subjects received a Nucleus Hybrid S8 (S8); 14 subjects received a Nucleus Hybrid L24 (L24); and 13 received a Nucleus Hybrid S12 (S12). Audiometric thresholds and consonant-nucleus-consonant (CNC) words were collected pre- and postoperatively for up to 15 years for the S8 subjects and for up to 7 years for the S12 and L24 subjects. AzBio Sentences in multi-talker babble was collected for up to 7 years on the S12 and L24 subjects., Results: Longitudinally, 83% of the S8 subjects, 92% of the S12 subjects, and 86% of the L24 subjects maintained a functional hearing pure-tone average (PTA) (125-500 Hz). Predicted change using a piecewise linear mixed model in PTA over time showed a postoperative linear decrease in hearing for each group until 0.5 years, after which the PTA stabilizes and is maintained. The averaged individual data for CNC and AzBio sentences show a significant improvement in scores by 0.25 to 0.5 years postimplantation, after which scores start to reach their maximum., Conclusion: This long-term study demonstrates that acoustic-electric processing hearing and improvement in speech understanding in quiet and in noise can be accomplished and sustained for many years with a short electrode CI., Level of Evidence: 2C. Laryngoscope, 128:473-481, 2018., (© 2017 The American Laryngological, Rhinological and Otological Society, Inc.)

Objectives/hypothesis: The concept of expanding electrical speech processing to those with more residual acoustic hearing with a less-invasive shorter cochlear implant (CI) has been ongoing since 1999. A multicenter study of the Nucleus Hybrid S8 CI took place between 2002 and 2011. This report describes the final outcomes of this clinical trial., Study Design: Multicenter, longitudinal, single-subject design., Methods: Eighty-seven subjects received a Nucleus Hybrid S8 CI in their poorer ear. Speech perception in quiet (Consonant-Nucleus-Consonant [CNC] words) and in noise (Bamford-Kowal-Bench Sentences-In-Noise [BKB-SIN]) were collected pre- and postoperatively at 3, 6, and 12 months. Subjective questionnaire data using the Abbreviated Profile for Hearing Aid Benefit (APHAB) were also collected., Results: Some level of hearing preservation was accomplished in 98% subjects, with 90% maintaining a functional low-frequency pure-tone average (LFPTA) at initial activation. By 12 months, five subjects had total hearing loss, and 80% of subjects maintained functional hearing. CNC words demonstrated that 82.5% and 87.5% of subjects had significant improvements in the hybrid and combined conditions, respectively. The majority had improvements with BKB-SIN. Results also indicated that as long as subjects maintained at least a severe LFPTA, there was significant improvement in speech understanding. Furthermore, all subjects reported positive improvements in hearing in three of the four subscales of the APHAB., Conclusions: The concept of hybrid speech processing has significant advantages for subjects with residual low-frequency hearing. In this study, the Nucleus Hybrid S8 provided improved word understanding in quiet and noise. Additionally, there appears to be stability of the residual hearing after initial activation of the device., Level of Evidence: 2c., (© 2016 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Preserved residual hearing in adult recipients of short electrode cochlear implants (CIs) contributes to improve perception of speech in noise as well as music. Recently, children and adolescents with sufficient low-frequency hearing but profound loss at higher frequencies enrolled in a FDA trial intended to evaluate the benefit of a short electrode device on the maintenance of residual hearing. This article reports on the perception of several music listening tasks by adolescents using electroacoustic hearing., Methods: Five adolescents (13-18 yr) with 18-24 months of electroacoustic experience, 73 children (LEC) and adolescents (LEA) who use traditional implants, and 87 children with normal hearing (NH) tested on 3 measures of music perception: Complex Pitch Ranking (PR-C); Melodic Error Detection (MED); Melody Recognition X Information Cue (MRIC). The participants with ipsilateral residual hearing were tested preoperatively at intervals up to 24 months., Results: Pitch ranking scores for the electroacoustic group were significantly better than the LEC and LEA (p < 0.0002 and p = 0.0076, respectively) and were not significantly different from the NH group. On the MED, although scores were more accurate than those of the LEC and LEA groups, they were not significantly better. For the MRIC, the electroacoustic group was significantly better than both LEA and LEC on melody with and without rhythm. NH subjects were significantly better than both LE groups, but not the electroacoustic group., Conclusion: Low-frequency information available to electroacoustic users was associated with more accurate perception on three pitch-based music listening tasks. Greater residual hearing during auditory development may also contribute to more "normal" mental representation of musical elements.

Background: Cochlear implant (CI) users have difficulty perceiving some intonation cues in speech and melodic contours because of poor frequency selectivity in the cochlear implant signal., Objectives: To assess perceptual accuracy of normal hearing (NH) children and pediatric CI users on speech intonation (prosody), melodic contour, and pitch ranking, and to determine potential predictors of outcomes., Hypothesis: Does perceptual accuracy for speech intonation or melodic contour differ as a function of auditory status (NH, CI), perceptual category (falling versus rising intonation/contour), pitch perception, or individual differences (e.g., age, hearing history)?, Method: NH and CI groups were tested on recognition of falling intonation/contour versus rising intonation/contour presented in both spoken and melodic (sung) conditions. Pitch ranking was also tested. Outcomes were correlated with variables of age, hearing history, HINT, and CNC scores., Results: The CI group was significantly less accurate than the NH group in spoken (CI, M = 63.1%; NH, M = 82.1%) and melodic (CI, M = 61.6%; NH, M = 84.2%) conditions. The CI group was more accurate in recognizing rising contour in the melodic condition compared with rising intonation in the spoken condition. Pitch ranking was a significant predictor of outcome for both groups in falling intonation and rising melodic contour; age at testing and hearing history variables were not predictive of outcomes., Conclusion: Children with CIs were less accurate than NH children in perception of speech intonation, melodic contour, and pitch ranking. However, the larger pitch excursions of the melodic condition may assist in recognition of the rising inflection associated with the interrogative form.

Objectives: This study examined speech recognition abilities of cochlear implant (CI) recipients in the spectrally complex listening condition of 3 contrasting types of background music, and compared performance based upon listener groups: CI recipients using conventional long-electrode devices, Hybrid CI recipients (acoustic plus electric stimulation), and normal-hearing adults., Methods: We tested 154 long-electrode CI recipients using varied devices and strategies, 21 Hybrid CI recipients, and 49 normal-hearing adults on closed-set recognition of spondees presented in 3 contrasting forms of background music (piano solo, large symphony orchestra, vocal solo with small combo accompaniment) in an adaptive test., Outcomes: Signal-to-noise ratio thresholds for speech in music were examined in relation to measures of speech recognition in background noise and multitalker babble, pitch perception, and music experience., Results: The signal-to-noise ratio thresholds for speech in music varied as a function of category of background music, group membership (long-electrode, Hybrid, normal-hearing), and age. The thresholds for speech in background music were significantly correlated with measures of pitch perception and thresholds for speech in background noise; auditory status was an important predictor., Conclusions: Evidence suggests that speech reception thresholds in background music change as a function of listener age (with more advanced age being detrimental), structural characteristics of different types of music, and hearing status (residual hearing). These findings have implications for everyday listening conditions such as communicating in social or commercial situations in which there is background music.

Background: The simulation of the CI (cochlear implant) signal presents a degraded representation of each musical instrument, which makes recognition difficult., Purpose: To examine the efficiency and effectiveness of three types of training on recognition of musical instruments as presented through simulations of the sounds transmitted through a CI., Research Design: Participants were randomly assigned to one of three training conditions: repeated exposure, feedback, and direct instruction., Study Sample: Sixty-six adults with normal hearing., Intervention: Each participant completed three training sessions per week, over a five-week time period, in which they listened to the CI simulations of eight different musical instruments., Data Collection and Analysis: Analyses on percent of instruments identified correctly showed statistically significant differences between recognition accuracy of the three training conditions (p < .01)., Results: those assigned to the direct instruction group showed the greatest improvement over the five-week training period as well as sustained improvement after training. The feedback group achieved the next highest level of recognition accuracy. The repeated exposure group showed modest improvement during the first three-week time period, but no subsequent improvements., Conclusions: These results indicate that different types of training are differentially effective with regard to improving recognition of musical instruments presented through a degraded signal, which has practical implications for the auditory rehabilitation of persons who use cochlear implants.

The research examined whether performance by adult cochlear implant recipients on a variety of recognition and appraisal tests derived from real-world music could be predicted from technological, demographic, and life experience variables, as well as speech recognition scores. A representative sample of 209 adults implanted between 1985 and 2006 participated. Using multiple linear regression models and generalized linear mixed models, sets of optimal predictor variables were selected that effectively predicted performance on a test battery that assessed different aspects of music listening. These analyses established the importance of distinguishing between the accuracy of music perception and the appraisal of musical stimuli when using music listening as an index of implant success. Importantly, neither device type nor processing strategy predicted music perception or music appraisal. Speech recognition performance was not a strong predictor of music perception, and primarily predicted music perception when the test stimuli included lyrics. Additionally, limitations in the utility of speech perception in predicting musical perception and appraisal underscore the utility of music perception as an alternative outcome measure for evaluating implant outcomes. Music listening background, residual hearing (i.e., hearing aid use), cognitive factors, and some demographic factors predicted several indices of perceptual accuracy or appraisal of music.

Objective: The purposes of this study were to (a) examine the accuracy of cochlear implant recipients who use different types of devices and signal processing strategies on pitch ranking as a function of size of interval and frequency range and (b) to examine the relations between this pitch perception measure and demographic variables, melody recognition, and speech reception in background noise., Design: One hundred fourteen cochlear implant users and 21 normal-hearing adults were tested on a pitch discrimination task (pitch ranking) that required them to determine direction of pitch change as a function of base frequency and interval size. Three groups were tested: (a) long electrode cochlear implant users (N = 101); (b) short electrode users that received acoustic plus electrical stimulation (A+E) (N = 13); and (c) a normal-hearing (NH) comparison group (N = 21). Pitch ranking was tested at standard frequencies of 131 to 1048 Hz, and the size of the pitch-change intervals ranged from 1 to 4 semitones. A generalized linear mixed model (GLMM) was fit to predict pitch ranking and to determine if group differences exist as a function of base frequency and interval size. Overall significance effects were measured with Chi-square tests and individual effects were measured with t-tests. Pitch ranking accuracy was correlated with demographic measures (age at time of testing, length of profound deafness, months of implant use), frequency difference limens, familiar melody recognition, and two measures of speech reception in noise., Results: The long electrode recipients performed significantly poorer on pitch discrimination than the NH and A+E group. The A+E users performed similarly to the NH listeners as a function of interval size in the lower base frequency range, but their pitch discrimination scores deteriorated slightly in the higher frequency range. The long electrode recipients, although less accurate than participants in the NH and A+E groups, tended to perform with greater accuracy within the higher frequency range. There were statistically significant correlations between pitch ranking and familiar melody recognition as well as with pure-tone frequency difference limens at 200 and 400 Hz., Conclusions: Low-frequency acoustic hearing improves pitch discrimination as compared with traditional, electric-only cochlear implants. These findings have implications for musical tasks such as familiar melody recognition.

Aim: The aims of this study were to examine the music perception abilities of Cochlear Nucleus Hybrid (acoustic plus electric stimulation) cochlear implant (CI) recipients and to compare their performance with that of normal-hearing (NH) adults and CI recipients using conventional long-electrode (LE) devices (Advanced Bionics: 90K, Clarion, CIIHF; Cochlear Corporation: CI24M, CI22, Contour; Ineraid). Hybrid CI recipients were compared with NH adults and LE CI recipients on recognition of (a) real-world melodies and (b) musical instruments., Patients and Methods: We tested 4 Hybrid CI recipients, 17 NH adults, and 39 LE CI recipients on open-set recognition of real-world songs presented with and without lyrics. We also tested 14 Hybrid CI recipients, 21 NH adults, and 174 LE CI recipients on closed-set recognition of 8 musical instruments playing a 7-note phrase., Results: On recognition of real-world songs, both the Hybrid recipients and NH listeners were significantly more accurate (p < 0.0001) than the LE CI recipients in the no lyrics condition, which required reliance on musical cues only. The LE group was significantly less accurate than either the Hybrid or NH group (p < 0.0001) on instrument recognition for low and high frequency ranges., Conclusions: These results, while preliminary in nature, suggest that preservation of low-frequency acoustic hearing is important for perception of real-world musical stimuli., (Copyright (c) 2006 S. Karger AG, Basel.)