Postlingually Deafened Adults 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.

Exploring the factors affecting music-related quality of life in post-lingual deaf adults with cochlear implants

Objective: To observe the feelings of listening to music and the importance of music in the daily life of post-lingual deaf adults with cochlear implants, and to explore the relevant influencing factors. Methods: This was a cross-sectional survey study. From January 2021 to August 2021,the Music-Related Quality of Life Scale was used to evaluate the music needs and music experiences of 63 post-lingual deaf adults who met the inclusion criteria, including 27 males and 36 females, aged (40.7±12.3) years, at the time of surgery (36.8±13.1) years, and with a preoperative hearing aid ineffective time of (3.9±5.8) years. Indicators analyzed included age, duration of ineffective preoperative hearing aid wear, preoperative music preference, duration of postoperative cochlear implant use, current hearing aid modality, and auditory rehabilitation outcomes. Whether the six factors mentioned above constituted an influence on the subjects' music listening was investigated using SPSS 25.0 statistical software. Results: All of the observations in the scale were correlated with a single factor. The two sub-dimensions of music experience section were related to the effect of auditory rehabilitation. In the importance section, the effect of auditory rehabilitation was the influential factor of the dimension of "participation importance", and the preoperative enjoyment of music was the relevant influential factor of the dimension of "perceived importance". There was a significant difference between the groups when they were grouped by the above factors (P value<0.05), while there was no statistically significance between the groups when they were grouped by other factors (P value>0.05). Conclusions: Post-lingual deaf adults show the need and attempt to listen to music after cochlear implantation. The effectiveness of auditory rehabilitation and the degree of music preference preoperatively are two important factors that influence music listening in implant recipients. Once the level of auditory communication has been restored to a certain degree, it is important to pay more attention to the needs of music for implant recipients and train them in time, especially for those with music preferences preoperatively.

Can Mandarin-speaking prelingual deaf adults benefit from cochlear implant?

Background With advances in cochlear implant (CI) technology, prelingual deaf adults may experience improved speech perception and quality of life (QoL). It is still a challenge for Mandarin-speaking CI user with tone recognition due to CI technology focused on intonation language. Objectives To evaluate the long-term post-CI auditory performance and social-emotional benefits in prelingual deaf Mandarin-speaking adults and the difference between them and post-lingual deaf adults. Material and Methods Fifty-five adult implanted ears were included (forty-six postlingual deaf group; nine prelingual deaf group). Post-CI long-term outcomes were using vowels, consonants, disyllabic words, Mandarin monosyllable words, categories of audiology performance, speech intelligibility rating, subjective social-emotional questionnaires. Results Post-CI auditory performance and speech intelligibility of prelingual deafness adults was significantly inferior to that of those with postlingual deafness. However, both groups presented improved social-emotional benefits, with no significant difference between both groups. Conclusions Adult CI recipients who deaf before the age of 4 can experience benefits in social-emotional life functioning, regardless of their limited auditory performance and speech intelligibility. Therefore, prelingual Mandarin-speaking deaf adults, especially those using oral communication, can be considered as relative indications for cochlear implantation. Significance To clarify and validate the benefits among Mandarin-speaking prelingual deaf adult recipients.

The Effects of Stimulus Repetition Rate on Electrically Evoked Auditory Brainstem Potentials in Postlingually Deafened Adult Cochlear Implant Recipients.

Background: By using outcome prediction scores, it is possible to distinguish between good and poor performers with cochlear implants (CI) after CI implantation. The reasons for poor performance, despite good basic conditions, can be manifold. On the one hand, the postoperative fitting may be inadequate; on the other, neurophysiological disease processes may impair speech understanding with a CI. These disease processes are not yet fully understood. In acoustics, it is known that the auditory brainstem responses (ABR) and their latencies and amplitudes allow differential diagnosis based on reference values for normal-hearing individuals. The aim of this study was to provide reference values for electrically evoked brainstem responses (EABRs) in terms of rate-dependent latencies and amplitudes. Methods: 20 ears of 18 experienced adult CI recipients with a predicted and measured good postoperative word recognition score were recruited from the clinic's patient pool. In the same stimulation mode and intensity we measured latencies and interpeak-latencies of EABRs and electrically evoked compound action potentials (ECAPs). With a defined supra-threshold stimulation intensity above the individual ECAP threshold, we applied stimulation at several rates between 11 and 91 stimuli per second. Results: We found rate dependences for EABR latency t3 and t5 in the order of 0.19 ms and 0.37 ms, respectively, while ECAP was not affected by rate. Correspondingly, the interpeak intervals' rate dependences for t5-t1, t5-t3 and t3-t1 were of the order of 0.37 ms, 0.18 ms and 0.19 ms. Comparing the EABR amplitudes between the stimulation rates 11/s and 81/s, we found that at 81/s the amplitudes were significantly reduced down: to 73% for A3 and 81% for A5. These rate dependences of latency and amplitude in EABR have characteristics comparable to those of acoustic ABR. Conclusions: These data may serve to provide reference values for EABR and ECAP latencies, interpeak intervals and amplitudes with respect to stimulation rate. Altered response patterns of ECAPs and EABRs to normalised stimulation modes could be used in the future to describe and classify neuropathological processes in a better-differentiated way.

Relationships Between the Auditory Nerve's Ability to Recover From Neural Adaptation, Cortical Encoding of and Perceptual Sensitivity to Within-channel Temporal Gaps in Postlingually Deafened Adult Cochlear Implant Users.

As a step toward identifying the origin of the across-electrode variation in within-channel gap detection thresholds (GDTs) measured in individual cochlear implant (CI) users, this study assessed the relationships between the auditory nerve's (AN's) ability to recover from neural adaptation, cortical encoding of and perceptual sensitivity to within-channel temporal gaps in postlingually deafened adult CI users. Study participants included 11 postlingually deafened adults with Cochlear Nucleus devices, including three bilaterally implanted participants. In each of the 14 ears tested, recovery from neural adaptation of the AN was measured using electrophysiological measures of the electrically evoked compound action potential at up to four electrode locations. The two CI electrodes in each ear showing the largest difference in the speed of adaptation recovery were selected for assessing within-channel temporal GDT. GDTs were measured using both psychophysical and electrophysiological procedures. Psychophysical GDTs were evaluated using a three-alternative, forced-choice procedure, targeting 79.4% correct on the psychometric function. Electrophysiological GDTs were measured using the electrically evoked auditory event-related potential (eERP) evoked by temporal gaps embedded in electrical pulse trains (i.e., the gap-eERP). Objective GDT was defined as the shortest temporal gap that could evoke a gap-eERP. Related-samples Wilcoxon Signed Rank test was used to compare psychophysical GDTs and objective GDTs measured at all CI electrode locations. It was also used to compare psychophysical GDTs and objective GDTs measured at the two CI electrode locations with different speeds or amounts of adaptation recovery of the AN. A Kendall Rank correlation test was used to assess the correlation between GDTs measured at the same CI electrode location using psychophysical or electrophysiological procedures. Objective GDTs were significantly larger than those measured using psychophysical procedures. There was a significant correlation between objective and psychophysical GDTs. GDTs could not be predicted based on the amount or the speed of adaptation recovery of the AN. Electrophysiological measures of the eERP evoked by temporal gaps can potentially be used to assess within-channel GDT in CI users who cannot provide reliable behavioral responses. The difference in adaptation recovery of the AN is not the primary factor accounting for the across-electrode variation in GDT in individual CI users.

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.

The Outcome of Cochlear Implantations in Deaf-Blind Patients: A Multicenter Observational Study.

This multicenter study aimed to evaluate the auditory and speech outcomes of cochlear implantation (CI) in deaf-blind patients compared with deaf-only patients. Retrospective cohort study. Multiple cochlear implant centers. The current study was conducted on 17 prelingual deaf-blind children and 12 postlingual deaf-blind adults who underwent CI surgery. As a control group, 17 prelingual deaf children and 12 postlingual deaf adults were selected. Cochlear implantation. Auditory and linguistic performances in children were assessed using the categories of auditory performance (CAP) and Speech Intelligibility Rating (SIR) scales, respectively. The word recognition score (WRS) was also used to measure speech perception ability in adults. The mean CAP, SIR, and WRS cores were compared between the deaf-only and deaf-blind groups before CI surgery and at "12 months" and "24 months" after device activation. Cohen's d was used for effect size estimation. We found no significant differences in the mean CAP and SIR scores between the deaf-blind and deaf-only children before the CI surgery. For both groups, SIR and CAP scores improved with increasing time after the device activation. The mean CAP scores in the deaf-only children were either equivalent or slightly higher than those of the deaf-blind children at "12 months post-CI" (3.94 ± 0.74 vs 3.24 ± 1.25; mean difference score, 0.706) and "24 months post-CI" (6.01 ± 0.79 vs 5.47 ± 1.06; mean difference score, 0.529) time intervals, but these differences were not statistically significant. The SIR scores in deaf-only implanted children were, on average, 0.870 scores greater than the deaf-blind children at "12 months post-CI" (2.94 ± 0.55 vs 2.07 ± 1.4; p = 0.01, d = 0.97) and, on average, 1.067 scores greater than deaf-blind children at "24 months post-CI" (4.35 ± 0.49 vs 3.29 ± 1.20; p = 0.002; d = 1.15) time intervals. We also found an improvement in WRS scores from the "preimplantation" to the "12-month post-CI" and "24-month post-CI" time intervals in both groups. Pairwise comparisons indicated that the mean WRS in the deaf-only adults was, on average, 10.61% better than deaf-blind implanted adults at "12 months post-CI" (62.33 ± 9.09% vs 51.71 ± 10.73%, p = 0.034, d = 1.06) and, on average, 15.81% better than deaf-blind adults at "24-months post-CI" (72.67 ± 8.66% vs 56.8 ± 9.78%, p = 0.002, d = 1.61) follow-ups. Cochlear implantation is a beneficial method for the rehabilitation of deaf-blind patients. Both deaf-blind and deaf-only implanted children revealed similar auditory performances. However, speech perception ability in deaf-blind patients was slightly lower than the deaf-only patients in both children and adults.

Characteristics of the Adaptation Recovery Function of the Auditory Nerve and Its Association With Advanced Age in Postlingually Deafened Adult Cochlear Implant Users.

This study aimed to (1) characterize the amount and the speed of recovery from neural adaptation at the auditory nerve (AN) and (2) assess their associations with advanced age in postlingually deafened adult cochlear implant users. Study participants included 25 postlingually deafened adult, Cochlear Nucleus device users, ranging in age between 24.83 and 83.21 years at the time of testing. The stimulus was a 100-ms pulse train presented at four pulse rates: 500, 900, 1800, and 2400 pulses per second (pps). The pulse trains were presented at the maximum comfortable level measured for the 2400-pps pulse train. The electrically evoked compound action potential (eCAP) evoked by the last pulse of the pulse train (i.e., the probe pulse) was recorded. The remaining pulses of the pulse train served as the pulse-train masker. The time interval between the probe pulse and the last pulse of the pulse-train masker [i.e., masker-probe-interval (MPI)] systematically increased from 0.359 ms up to 256 ms. The adaptation recovery function (ARF) was obtained by plotting normalized eCAP amplitudes (re: the eCAP amplitude measured at the MPI of 256 ms) as a function of MPIs. The adaptation recovery ratio (ARR) was defined as the ratio between the eCAP amplitude measured at the MPI of 256 ms and that measured for the single-pulse stimulus presented at the same stimulation level. The time constants of the ARF were estimated using a mathematical model with an exponential function with up to three components. Generalized Linear Mixed effects Models were used to compare ARRs and time constants measured at different electrode locations and pulse rates, as well as to assess the effect of advanced age on these dependent variables. There were three ARF types observed in this study. The ARF type observed in the same study participant could be different at different electrode locations and/or pulse rates. Substantial variations in both the amount and the speed of neural adaptation recovery among study participants were observed. The ARR was significantly affected by pulse rate but was not affected by electrode location. The effect of electrode location on the time constants of the ARF was not statistically significant. Pulse rate had a statistically significant effect on τ 1, but not on τ 2 or τ 3 . There was no statistically significant effect of age on the ARR or the time constants of the ARF. Neural adaptation recovery processes at the AN demonstrate substantial variations among human cochlear implant users. The recovery pattern can be nonmonotonic with up to three phases. While the amount of neural adaptation recovery decreases as pulse rate increases, only the speed of the first phase of neural adaptation recovery is affected by pulse rate. Electrode location or advanced age has no robust effect on neural adaptation recovery processes at the level of the AN for a 100-ms pulse-train masker with pulse rates of 500 to 2400 pps. The lack of sufficient participants in this study who were 40 years of age or younger at the time of testing might have precluded a thorough assessment of the effect of advanced age.

Analysis of Neural Interface When Using Modiolar Electrode Stimulation. Radiological Evaluation, Trans-Impedance Matrix Analysis and Effect on Listening Effort in Cochlear Implantation.

Background: The proximity of the electrode to the modiolar wall may be of interest to investigate the effect of pitch discrimination. This research establishes the relation between these factors and whether perimodiolar positions may provide benefits regarding improved electrode discrimination. Methods: A prospective randomized study including 24 post-lingual deaf adults was performed. A psychoacoustic study was done by using a psychoacoustic research platform. Radiological study, and a cone-beam computed tomography was used to assess post cochlear implantation electrodes’ position. Trans-impedance matrix (TIM) analysis was performed after cochlear implant insertion in all cases, and pupillometry test was also performed. Results: 12 patients received a slim perimodiolar electrode array, and 12 patients received a straight electrode array. Although all the patients showed similar speech test results after 12 months follow-up, those implanted with a perimodiolar electrode obtained better scores in electrode discrimination test and pupillometry test, and showed more homogenous TIM patterns. Conclusions: The better positioning of the electrode array seams to provide a better hearing resolution and less listening effort trans-impedance matrix seems to be a useful tool to analyze positioning of the perimodiolar array.

High-frequency Cochlear Nerve Deficit Region: Relationship With Deaf Duration and Cochlear Implantation Performance in Postlingual Deaf Adults.

To analyze the changes of cochlear nerve diameter and the presence of a cochlear nerve deficit at a high-frequency region and investigate their effects on cochlear implant (CI) performance in postlingual deaf adults. Retrospective. Tertiary care academic center. Eighty-three postlingual deaf adults with no labyrinthine anomalies or cognitive deficits who received a CI with perimodiolar electrodes from a single manufacturer. We evaluated the changes of cochlear nerve diameter and the presence of a "tail sign," defined as identifiable nerve fibers originating from the far basal turn of the cochlea, which represents the presence of cochlear nerve at a high-frequency region in magnetic resonance imaging, on monosyllabic word recognition scores. The cochlear nerve diameter showed a positive correlation with word recognition scores (maximum diameter, R2 = 0.26, p < 0.01; minimum diameter, R2 = 0.26, p < 0.01), but a negative correlation with deaf duration. Recipients with a positive tail sign performed better (73 ± 19%) than those without (45 ± 24%, p < 0.01). A positive tail sign was more commonly found in good performers (52 of 62, 84%) than in poor performers (5 of 21, 24%, p < 0.01). Favorable outcomes could be anticipated in postlingual deaf adults with a large cochlear nerve diameter and positive tail sign. A presence of cochlear nerve at a high-frequency region may be an imaging marker for predicting good CI performance.

Word and Nonword Reading Efficiency in Postlingually Deafened Adult Cochlear Implant Users.

This study tested the hypotheses that 1) experienced adult cochlear implants (CI) users demonstrate poorer reading efficiency relative to normal-hearing controls, 2) reading efficiency reflects basic, underlying neurocognitive skills, and 3) reading efficiency relates to speech recognition outcomes in CI users. Weak phonological processing skills have been associated with poor speech recognition outcomes in postlingually deaf adult CI users. Phonological processing can be captured in nonauditory measures of reading efficiency, which may have wide use in patients with hearing loss. This study examined reading efficiency in adults CI users, and its relation to speech recognition outcomes. Forty-eight experienced, postlingually deaf adult CI users (ECIs) and 43 older age-matched peers with age-normal hearing (ONHs) completed the Test of Word Reading Efficiency (TOWRE-2), which measures word and nonword reading efficiency. Participants also completed a battery of nonauditory neurocognitive measures and auditory sentence recognition tasks. ECIs and ONHs did not differ in word (ECIs: M = 78.2, SD = 11.4; ONHs: M = 83.3, SD = 10.2) or nonword reading efficiency (ECIs: M = 42.0, SD = 11.2; ONHs: M = 43.7, SD = 10.3). For ECIs, both scores were related to untimed word reading with moderate to strong effect sizes (r = 0.43-0.69), but demonstrated differing relations with other nonauditory neurocognitive measures with weak to moderate effect sizes (word: r = 0.11-0.44; nonword: r = (-)0.15 to (-)0.42). Word reading efficiency was moderately related to sentence recognition outcomes in ECIs (r = 0.36-0.40). Findings suggest that postlingually deaf adult CI users demonstrate neither impaired word nor nonword reading efficiency, and these measures reflect different underlying mechanisms involved in language processing. The relation between sentence recognition and word reading efficiency, a measure of lexical access speed, suggests that this measure may be useful for explaining outcome variability in adult CI users.

Assessment of speech perception and quality of life after cochlear implant in postlingual deaf adults

Objective:The study is aimed to evaluate impacts of cochlear implantation on speech perception and quality of life in postlingual deaf adults, and to explore the correlation between speech perception and quality of life using Nijimegen Cochlear Implantation Questionnaire and Mandarin version of Minimum Speech Test Battery. Method:Thirty-six postlingual deafpatients were recruited, including 20 males and 16 females. Patient age was 20 to 72 years old（52±16） when CI was implanted, and the hearing loss duration was 2 to 25 years（14±6） before cochlear implantation. The single syllable recognition rate score were tested by using Mandarin version of Minimum Speech Test Battery, and the quantify quality of life was tested by using Nijimegen Cochlear Implantation Questionnaire. Result:Speech recognition and quality of life have significantly improved in patients with CI after cochlear implantiont. The scores of basic sound perception, advanced sound perception, speech ability, self-confidence, social activity ability, and social ability have improved, but the differences were not statistically significant. The Mandrin single-syllable recognition rate scores were related to basic sound perception（r=-0.36; P=0.004）, advanced sound perception（r=-0.41; P=0.002）, and speech ability（r=-0.67; P=0.001）, and the differences are statistically significant. Conclusion:The postlingual deafnesses ability of auditory, speech perception and the quality of life have improved significantly in patients with CI after cochlear implantiont.

Acoustic Voice Analysis in Postlingual Deaf Adult Cochlear Implant Users: A Within-Group Comparison Study

Cochlear implantation (CI) improves the quality of voice and speech output. However, there are various factors that may interfere with the use of CI to accede desirable voice outcomes. The primary aim of the current study was first to measure three acoustic voice outcomes in postlingual deaf adult CI users who were Persian-speaking, and then, to compare these according to surgery- and auditory-related factors. Of interest was also to determine whether these acoustic measures were influenced by surgery- and auditory-related factors. A number of 113 postlingual deaf adults with CI were recruited. The voice samples were recorded in the same silent room to equalize the noise of the environment. The measures of interest were analyzed with the Praat software. Our findings revealed that time duration of CI use (P ≤ 0.008), pattern of deafness onset (P ≤ 0.011), and the interaction between them (P ≤ 0.022) significantly affected all vocal parameters. This means that the quality of voice was significantly better in the participants using CI for more than 2 years than in those using CIs for less than 2 years. On the other hand, patients suffering sudden postlingual deafness for less than 2 years had the best acoustic voice parameters compared with those suffering gradual postlingual deafness for more than 2 years. Some of the surgery- and auditory-related factors could be the reason for changes of voice parameters in postlingual deaf adult CI users.

Do Personality Factors Assessed Before Cochlear Implantation Predict Hearing-Related Quality Of Life After Cochlear Implantation in Postlingually Deafened Adults?

Studies have shown that cochlear implants improve deaf patients' hearing-related quality of life (hrQoL), but the degree of improvement varies considerably between patients. This study investigated whether personality factors contribute to hrQoL outcome after cochlear implantation. Fifty adult patients with postlingual hearing loss who received a unilateral cochlear implant were administered the Neuroticism-Extraversion-Openness Five-Factor Inventory (NEO-FFI; a personality inventory) and the Nijmegen Cochlear Implant Questionnaire (NCIQ; a hrQoL questionnaire). The NEO-FFI was administered only before implantation; the NCIQ was administered before implantation and 12 months after implant activation. A linear regression analysis was computed to detect whether NCIQ scores at 12 months were predicted by the NEO-FFI personality factors (i.e., Extraversion, Neuroticism, Openness to Experience, Agreeableness, and Conscientiousness) assessed before implantation. HrQoL scores had significantly improved 12 months after cochlear implantation in all subdomains of the NCIQ. Of the five personality factors, solely Neuroticism was negatively associated to the NCIQ subdomain self-esteem (β = -0.34; p = 0.013) at 12 months after cochlear implantation. While significant improvement of hrQoL was seen 12 months after implant activation, this improvement was barely predicted by the Big-Five personality traits measured before implantation. Only Neuroticism was found to moderately influence postimplantation hrQoL in our patients, in the way that higher degrees of Neuroticism tend to go along with lower degrees of self-esteem (as conceptualized by the NCIQ). The failure to detect personality effects on hrQoL could partly be due to the low levels of Extraversion and Openness to Experience observed in our sample of patients with hearing loss.

Evaluation of Mandarin Chinese Speech Recognition in Adults with Cochlear Implants Using the Spectral Ripple Discrimination Test.

BackgroundThe aim of this study was to explore the value of the spectral ripple discrimination test in speech recognition evaluation among a deaf (post-lingual) Mandarin-speaking population in China following cochlear implantation.Material/MethodsThe study included 23 Mandarin-speaking adult subjects with normal hearing (normal-hearing group) and 17 deaf adults who were former Mandarin-speakers, with cochlear implants (cochlear implantation group). The normal-hearing subjects were divided into men (n=10) and women (n=13). The spectral ripple discrimination thresholds between the groups were compared. The correlation between spectral ripple discrimination thresholds and Mandarin speech recognition rates in the cochlear implantation group were studied.ResultsSpectral ripple discrimination thresholds did not correlate with age (r=−0.19; p=0.22), and there was no significant difference in spectral ripple discrimination thresholds between the male and female groups (p=0.654). Spectral ripple discrimination thresholds of deaf adults with cochlear implants were significantly correlated with monosyllabic recognition rates (r=0.84; p=0.000).ConclusionsIn a Mandarin Chinese speaking population, spectral ripple discrimination thresholds of normal-hearing individuals were unaffected by both gender and age. Spectral ripple discrimination thresholds were correlated with Mandarin monosyllabic recognition rates of Mandarin-speaking in post-lingual deaf adults with cochlear implants. The spectral ripple discrimination test is a promising method for speech recognition evaluation in adults following cochlear implantation in China.

Limitation of High Pitch Sound Perception in Nontumor Patients with Auditory Brainstem Implantation

Background and Objectives Auditory brainstem implantation (ABI) is another option for hearing rehabilitation in non-neurofibromatosis type 2 patients who cannot undergo cochlear implantation (CI). However, the average performance of ABI is worse than that of CI. We analyzed the psycho-electrical parameters of each electrode and psycho-acoustic response to different frequency sounds in nontumor patients with ABI. Subjects and Method Sixteen patients with ABI from July 2008 to May 2013 were included in the study. They were followed up for 4 to 56 months. Among them, 12 were prelingual deaf with a narrow internal auditory canal or cochlear ossification. The remaining four were postlingual deaf adults with severely ossified cochleae. We analyzed the electrical parameters [impedance, threshold level (T level), and dynamic range] of each of the 12 electrodes. We also evaluated the sound field pure-tone threshold, Ling 6 sound detection-identification test (Ling 6 test), and pitch ranking data of these patients. Results The impedance, T level, and dynamic range did not significantly differ among electrodes. However, the pure-tone threshold to sound field stimulation was elevated in the high tone area, where more variables were found than in the low frequency area. Patients could not identify /S/ and /Sh/ sounds in the Ling 6 test. The mean T level and the dynamic range of the three highest pitch-perceiving electrodes in each patient was higher and narrower, respectively, than those of the three lowest pitch-perceiving electrodes. Conclusion The nontumor patients with ABI have difficulty perceiving high pitch sound. More sophisticated penetrating type electrodes and, if possible, bimodal stimulation with CI, could be considered. Key words: Auditory brainstem implantation ㆍ Cochlear ossification ㆍ Narrow internal auditory canal ㆍ nontumor ㆍ Outcomes.

The Voice Track multiband single-channel modified Wiener-filter noise reduction system for cochlear implants: patients' outcomes and subjective appraisal

Objective: The aim of this study was to evaluate the potential improvements of speech perception and sound quality provided by a multiband single channel noise-reduction algorithm based on the modified Wiener-filter adapted to cochlear implant sound processing. Design: This study was a longitudinal trial with a repeated-measures design. Outcome measures were performed on the first day when the noise reduction feature was provided and after a one month habituation period. Objective measures included pure-tone thresholds and vocal audiometry assessments. Speech perception was measured in quiet and in the presence of two types of noise: a stationary speech shaped noise and a two-talker cocktail noise. Subjective sound quality was assessed using a ten item questionnaire. Study Sample: Thirteen post-lingual deaf adults, experienced users of a cochlear implant system, took part in this study. Results: The noise-reduction algorithm provided a benefit for the perception of speech presented in a stationary speech shaped noise and an overall improvement in subjective sound quality ratings. Conclusions: It was shown that a single channel noise reduction system based on a modified Wiener-filter approach can improve speech in noise perception performance and subjective sound quality in cochlear implant patients.

Cross-Modal and Intra-Modal Characteristics of Visual Function and Speech Perception Performance in Postlingually Deafened, Cochlear Implant Users.

Evidence of visual-auditory cross-modal plasticity in deaf individuals has been widely reported. Superior visual abilities of deaf individuals have been shown to result in enhanced reactivity to visual events and/or enhanced peripheral spatial attention. The goal of this study was to investigate the association between visual-auditory cross-modal plasticity and speech perception in post-lingually deafened, adult cochlear implant (CI) users. Post-lingually deafened adults with CIs (N = 14) and a group of normal hearing, adult controls (N = 12) participated in this study. The CI participants were divided into a good performer group (good CI, N = 7) and a poor performer group (poor CI, N = 7) based on word recognition scores. Visual evoked potentials (VEP) were recorded from the temporal and occipital cortex to assess reactivity. Visual field (VF) testing was used to assess spatial attention and Goldmann perimetry measures were analyzed to identify differences across groups in the VF. The association of the amplitude of the P1 VEP response over the right temporal or occipital cortex among three groups (control, good CI, poor CI) was analyzed. In addition, the association between VF by different stimuli and word perception score was evaluated. The P1 VEP amplitude recorded from the right temporal cortex was larger in the group of poorly performing CI users than the group of good performers. The P1 amplitude recorded from electrodes near the occipital cortex was smaller for the poor performing group. P1 VEP amplitude in right temporal lobe was negatively correlated with speech perception outcomes for the CI participants (r = -0.736, P = 0.003). However, P1 VEP amplitude measures recorded from near the occipital cortex had a positive correlation with speech perception outcome in the CI participants (r = 0.775, P = 0.001). In VF analysis, CI users showed narrowed central VF (VF to low intensity stimuli). However, their far peripheral VF (VF to high intensity stimuli) was not different from the controls. In addition, the extent of their central VF was positively correlated with speech perception outcome (r = 0.669, P = 0.009). Persistent visual activation in right temporal cortex even after CI causes negative effect on outcome in post-lingual deaf adults. We interpret these results to suggest that insufficient intra-modal (visual) compensation by the occipital cortex may cause negative effects on outcome. Based on our results, it appears that a narrowed central VF could help identify CI users with poor outcomes with their device.

The role of preoperative imaging for cochlear implantation in postlingually deafened adults.

Preoperative imaging is standard practice for cochlear implant candidacy. Postlingually deafened adults rarely have temporal bone abnormalities that alter management. To determine the role of preoperative imaging for cochlear implantation in postlingually deafened adults. We hypothesize that imaging does not alter management in the absence of history or physical examination findings suggestive of an anatomic abnormality. Nested case-control study. We identified postlingually deafened adults with preoperative imaging and cochlear implantation at our institution from 1995 to 2008. Controls had a negative history and normal exam. Cases had suggestive history or exam. Imaging studies and operative records were reviewed. Approximately 164 patients met inclusion criteria-59 cases and 109 controls. Mean age at onset of hearing loss was 30.4 years (range, 0-73 yr), mean age at onset of deafness was 54.1 years (range, 9-89 yr), and mean age at implantation was 61.5 years (range, 20.6-89.7 yr). Twenty cases (34%) and 17 controls (16%) had abnormal imaging (p = 0.001). Six cases (8.5%) and 2 controls (1.8%) had changes in their management as a result of the imaging findings (p = 0.023). Both control patients had incidentally detected acoustic neuromas, which altered the side of the cochlear implantation. There was a strong association between preoperative history and exam findings and abnormality on imaging (p = 0.007). Abnormalities were 3 times more likely in patients with a positive history or exam (OR = 2.98; 95% CI, 1.36-6.54). In patients with a negative history and examination, imaging rarely alters management. MRI may detect incidental vestibular schwannomas in patients with asymmetric hearing losses. 3b, Individual case-control study.

Morphological brain network assessed using graph theory and network filtration in deaf adults

Prolonged deprivation of auditory input can change brain networks in pre- and postlingual deaf adults by brain-wide reorganization. To investigate morphological changes in these brains voxel-based morphometry, voxel-wise correlation with the primary auditory cortex, and whole brain network analyses using morphological covariance were performed in eight prelingual deaf, eleven postlingual deaf, and eleven hearing adults. Network characteristics based on graph theory and network filtration based on persistent homology were examined.Gray matter density in the primary auditor cortex was preserved in prelingual deafness, while it tended to decrease in postlingual deafness. Unlike postlingual, prelingual deafness showed increased bilateral temporal connectivity of the primary auditory cortex compared to the hearing adults.Of the graph theory-based characteristics, clustering coefficient, betweenness centrality, and nodal efficiency all increased in prelingual deafness, while all the parameters of postlingual deafness were similar to the hearing adults. Patterns of connected components changing during network filtration were different between prelingual deafness and hearing adults according to the barcode, dendrogram, and single linkage matrix representations, while these were the same in postlingual deafness. Nodes in fronto-limbic and left temporal components were closely coupled, and nodes in the temporo-parietal component were loosely coupled, in prelingual deafness. Patterns of connected components changing in postlingual deafness were the same as hearing adults. We propose that the preserved density of auditory cortex associated with increased connectivity in prelingual deafness, and closer coupling between certain brain areas, represent distinctive reorganization of auditory and related cortices compared with hearing or postlingual deaf adults. The differential network reorganization in the prelingual deaf adults could be related to the absence of auditory speech experience.