Adult Cochlear Implant Users Research Articles

Environmental sound perception in adults with hearing loss and cochlear implants

Perception of environmental sounds is crucial for safety, independence, and quality-of-life among adults with hearing loss. The objective of this study was (Experiment 1) to longitudinally assess environmental sound recognition (ESR) in a sample of postlingually deafened adults before and after receiving cochlear implants (CIs) and (Experiment 2) to cross-sectionally assess the ability of adults with CIs to identify safety-relevant environmental sounds. For Experiment 1, 20 postlingually deafened adults were tested with hearing aids on the Familiar Environmental Sound Test-Identification pre-CI and 6 months post-CI. A subset of 11 participants were also tested 12-months post-CI. Average ESR accuracy pre-CI (M = 63.60%) was not significantly different from ESR accuracy 6-months (M = 65.40%) or 12-months (M = 69.09%) post-CI. For Experiment 2, 21 experienced adult CI users completed an ESR test consisting of 42 common environmental sounds, 28 of which were safety-relevant, along with 14 control sounds. Overall, ESR accuracy was 57% correct for safety-relevant sounds and 55% correct for control sounds. These findings suggest mediocre ESR in postlingual adult CI users for safety-relevant and other environmental sounds. Deficits in identification of environmental sounds may put CI listeners at increased safety risks and may require specific rehabilitation to improve outcomes.

From sounds to scenes: Comprehension of environmental sounds by cochlear implant users

Performance outcomes for cochlear implant (CI) users traditionally focus on measures of speech perception. However, existing research indicates that environmental sound identification tasks also remain challenging for adult CI users compared to normal-hearing (NH) or hearing-impaired (HI) peers. In contrast, anecdotal reports indicate that environmental sound perception improves post-implantation. Methodological choices may contribute to this discrepancy; CI users may be benefiting from more integrative higher-level processes that are not adequately measured by source identification tasks. This study employs two alternative tasks that are designed to assess perception of the semantic properties of environmental sounds. The first is a comprehension tasks, which requires listeners to make inferences about naturalistic sound scene recordings (e.g. which other activities might you expect to take place, or at which time of day does this scene most likely occur). The second task presents a triplet of isolated environmental sound recordings and requires participants to select the sound that does not belong. Preliminary data indicate that CI users are able to perform the tasks with varying levels of proficiency relative to NH and HI listeners. Comprehension tasks focused on context-dependent semantic processing may, thus, complement findings from more traditional single-sound identification tasks.

An Overview of Telepractice Applications for Comprehensive Cochlear Implant Service Delivery

Purpose:Numerous follow-up appointments are required to program a cochlear implant (CI) sound processor and monitor the patient's progress over time, particularly within the first year of implantation. This, coupled with the specialty nature of CI service delivery and sparsely located clinics, can pose burdens on recipients' time and access to necessary resources for consistent follow-up. Advances in the application of telepractice for CI service delivery have evolved and expanded over recent years, with further utilization spurred by the COVID-19 pandemic that emerged in late 2019. This review article provides a summary of telepractice applications for adult and pediatric CI processor programming, impedance, and electrically evoked compound action potential testing, speech-perception testing, evaluations of patient and clinician experiences, troubleshooting, and aural rehabilitation for CI recipients. Future directions and opportunities for further implementation of telepractice for CI service delivery are discussed.Conclusions:Studies to date suggest that telepractice can be reliably used for remote sound processor programming for both children and adults, impedance and evoked compound action potential measures, speech-perception testing in adult CI users, and self-monitoring. However, further technological advancements are needed to make remote speech-perception testing more easily implemented, and well-controlled studies are needed to better evaluate the efficacies of aural rehabilitation through teletherapy, particularly for children.

Perception of timbre in adult Cochlear implant users: Comparison of Iranian and Western musical instruments

Objectives Cochlear implants (CI) have dramatically improved speech perception for patients with sensorineural hearing impairment. However, listening to music is a great challenge for them. This study examined the perception and appraisal of Iranian musical instruments comparing with similar Western instruments. Methods Eleven adult CI users and 25 normal hearing (NH) individuals participated in this study. Musical stimuli of three commonly heard instrument pairs were prepared. Participants were asked to identify the instruments and rate their appraisal on a ten-point Likert scale (0 = dislike very much, 10 = like very much). Results The instrument recognition rate was 40.6% among the CI users, and the mean appraisal score was 5.2 ± 2.7. NH listeners had none significant higher scores on both tasks with a recognition rate of 50.0% and the mean appraisal score of 6.9 ± 1.5. Iranian instruments were more recognized in both groups. Regarding their appraisal, the mean score for both types was almost equal in the NH group, while CI users more appraised Iranian instruments. Conclusion In addition to better recognition of Iranian instruments, they were particularly better appraised in the CI group. Iranian instruments provide suitable musical pieces for CI recipients that can be considered in rehabilitation programs.

Strategic Pauses Relieve Listeners from the Effort of Listening to Fast Speech: Data Limited and Resource Limited Processes in Narrative Recall by Adult Users of Cochlear Implants.

Speech that has been artificially accelerated through time compression produces a notable deficit in recall of the speech content. This is especially so for adults with cochlear implants (CI). At the perceptual level, this deficit may be due to the sharply degraded CI signal, combined with the reduced richness of compressed speech. At the cognitive level, the rapidity of time-compressed speech can deprive the listener of the ordinarily available processing time present when speech is delivered at a normal speech rate. Two experiments are reported. Experiment 1 was conducted with 27 normal-hearing young adults as a proof-of-concept demonstration that restoring lost processing time by inserting silent pauses at linguistically salient points within a time-compressed narrative ("time-restoration") returns recall accuracy to a level approximating that for a normal speech rate. Noise vocoder conditions with 10 and 6 channels reduced the effectiveness of time-restoration. Pupil dilation indicated that additional effort was expended by participants while attempting to process the time-compressed narratives, with the effortful demand on resources reduced with time restoration. In Experiment 2, 15 adult CI users tested with the same (unvocoded) materials showed a similar pattern of behavioral and pupillary responses, but with the notable exception that meaningful recovery of recall accuracy with time-restoration was limited to a subgroup of CI users identified by better working memory spans, and better word and sentence recognition scores. Results are discussed in terms of sensory-cognitive interactions in data-limited and resource-limited processes among adult users of cochlear implants.

Evaluation of the Effect of Musical Perception Activities on Speech Perception in Adult Cochlear Implant Users.

This study aimed to evaluate clinical musical perception, analyze the relationship between speech recognition and music perception, and investigate the effects of a three-month musical perception activities on these parameters in adult cochlear implant (CI) users with post-lingual hearing loss. Free-field hearing and speech tests in a quiet environment, the Turkish matrix test, and the Turkish version of the clinical assessment of musical perception test were performed on 18 adult unilateral CI users before and after the three-month music training. Results were compared with those of 18 healthy controls. Prior to the musical perception activities, word recognition scores, Turkish matrix test results, and 500, 1000, and 6000 Hz free-field hearing thresholds were significantly correlated with the clinical assessment of musical perception test scores in the CI group (p<0.047). Timbre recognition scores (p=0.019) had improved significantly in the CI group after the three-month musical perception activities. On the other hand, timbre recognition scores had significantly affected the Turkish matrix test results (R2adjusted=0.56). Our study showed that speech perception in noise and clinical musical perception measurements affected each other in CI users. The inclusion of musical perception activities to support an auditory rehabilitation program may contribute to increased speech recognition skills in noise.

Preoperative Reading Efficiency as a Predictor of Adult Cochlear Implant Outcomes.

1) Scores of reading efficiency (the Test of Word Reading Efficiency, second edition) obtained in adults before cochlear implant surgery will be predictive of speech recognition outcomes 6 months after surgery; and 2) Cochlear implantation will lead to improvements in language processing as measured through reading efficiency from preimplantation to postimplantation. Adult cochlear implant (CI) users display remarkable variability in speech recognition outcomes. "Top-down" processing-the use of cognitive resources to make sense of degraded speech-contributes to speech recognition abilities in CI users. One area that has received little attention is the efficiency of lexical and phonological processing. In this study, a visual measure of word and nonword reading efficiency-relying on lexical and phonological processing, respectively-was investigated for its ability to predict CI speech recognition outcomes, as well as to identify any improvements after implantation. Twenty-four postlingually deaf adult CI candidates were tested on the Test of Word Reading Efficiency, Second Edition preoperatively and again 6 months post-CI. Six-month post-CI speech recognition measures were also assessed across a battery of word and sentence recognition. Preoperative nonword reading scores were moderately predictive of sentence recognition outcomes, but real word reading scores were not; word recognition scores were not predicted by either. No 6-month post-CI improvement was demonstrated in either word or nonword reading efficiency. Phonological processing as measured by the Test of Word Reading Efficiency, Second Edition nonword reading predicts to a moderate degree 6-month sentence recognition outcomes in adult CI users. Reading efficiency did not improve after implantation, although this could be because of the relatively short duration of CI use.

The evaluation of cochlear implant users’ acoustic change detection ability

Objectives This study aimed to evaluate the relationship between behaviourally acquired Acoustic Change Detection Test (ACDT) responses and electrophysiologically obtained Acoustic Change Complex (ACC) responses in participants with Cochlear Implant (CI). Methods 28 unilateral adult CI users (mean age 41) participated in the study. In behavioural test session, ACDT and speech tests were administered. In electrophysiological test session, sound onset and ACC responses of participants stimulated by/ui/speech structure were recorded and N1–P2 peak-to-peak amplitude and N1 latencies were determined. Results No significant correlation was found between individuals’ behavioural and electrophysiological responses but it was observed that individuals dived into two clusters in terms of ACDT responses (p < 0.05). A statistically significant difference was found between the mean ACC amplitudes of the clusters. No statistically significant difference was observed between the mean ACC N1 latency findings of the clusters, suggesting that ACC amplitude may be a better predictor than latency in auditory discrimination. Conclusion ACC measurement may be a potential clinical tool to evaluate auditory discrimination performance in individuals with CI, but using the electrophysiological and behavioural tests together may provide a more holistic perspective.

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.

Assessing the Relationship Between Pitch Perception and Neural Health in Cochlear Implant Users.

Various neural health estimates have been shown to indicate the density of spiral ganglion neurons in animal and modeling studies of cochlear implants (CIs). However, when applied to human CI users, these neural health estimates based on psychophysical and electrophysiological measures are not consistently correlated with each other or with the speech recognition performance. This study investigated whether the neural health estimates have stronger correlations with the temporal and place pitch sensitivity than with the speech recognition performance. On five electrodes in 12 tested ears of eight adult CI users, polarity effect (PE), multipulse integration (MPI), and interphase gap (IPG) effect on the amplitude growth function (AGF) of electrically evoked compound action potential (ECAP) were measured to estimate neural health, while thresholds of amplitude modulation frequency ranking (AMFR) and virtual channel ranking (VCR) were measured to indicate temporal and place pitch sensitivity. AzBio sentence recognition in noise was measured using the clinical CI processor for each ear. The results showed significantly poorer AMFR and VCR thresholds on the basal electrodes than on the apical and middle electrodes. Across ears and electrodes, only the IPG offset effect on ECAP AGF had a nearly significant negative correlation with the VCR threshold after removing the outliers. No significant across-ear correlations were found between the mean neural health estimates, mean pitch-ranking thresholds, and AzBio sentence recognition score. This study suggests that the central axon demyelination reflected by the IPG offset effect may be important for the place pitch sensitivity of CI users and that the IPG offset effect may be used to predict the perceptual resolution of virtual channels for CI programming.

Identification Accuracy of Safety-Relevant Environmental Sounds in Adult Cochlear Implant Users.

Examine cochlear implant (CI) users' ability to identify safety-relevant environmental sounds, imperative for safety, independence, and personal well-being. Twenty-one experienced adult CI users completed an Environmental Sound Identification (ESI) test consisting of 42 common environmental sounds, 28 of which were relevant to personal safety, along with 14 control sounds. Prior to sound identification, participants were shown sound names and asked to rate the familiarity and, separately, relevance to safety of each corresponding sound on a 1-5 scale. Overall ESI accuracy was 57% correct for the safety-relevant sounds and 55% correct for control sounds. Participants rated safety-relevant sounds as more important to safety and more familiar than the non-safety sounds. ESI accuracy significantly correlated with familiarity ratings. The present findings suggest mediocre ESI accuracy in postlingual adult CI users for safety-relevant and other environmental sounds. Deficits in the identification of these sounds may put CI listeners at increased risk of accidents or injuries and may require a specific rehabilitation program to improve CI outcomes. 4 Laryngoscope, 133:2388-2393, 2023.

Phoneme Categorization in Prelingually Deaf Adult Cochlear Implant Users.

Phoneme categorization (PC) for voice onset time and second formant transition was studied in adult cochlear implant (CI) users with early-onset deafness and hearing controls. Identification and discrimination tasks were administered to 30 participants implanted before 4 years of age, 21 participants implanted after 7 years of age, and 21 hearing individuals. Distinctive identification and discrimination functions confirmed PC within all groups. Compared to hearing participants, the CI groups generally displayed longer/higher category boundaries, shallower identification function slopes, reduced identification consistency, and reduced discrimination performance. A principal component analysis revealed that identification consistency, discrimination accuracy, and identification function slope, but not boundary location, loaded on a single factor, reflecting general PC performance. Earlier implantation was associated with better PC performance within the early CI group, but not the late CI group. Within the early CI group, earlier implantation age but not PC performance was associated with better speech recognition. Conversely, within the late CI group, better PC performance but not earlier implantation age was associated with better speech recognition. Results suggest that implantation timing within the sensitive period before 4 years of age partly determines the level of PC performance. They also suggest that early implantation may promote development of higher level processes that can compensate for relatively poor PC performance, as can occur in challenging listening conditions.

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.

Within- and across-frequency temporal processing and speech perception in cochlear implant users.

Cochlear implant (CI) recipient's speech perception performance is highly variable and is influenced by temporal processing abilities. Temporal processing is commonly assessed using a behavioral task that requires the participant to detect a silent gap with the pre- and post-gap stimuli of the same frequency (within-frequency gap detection) or of different frequencies (across-frequency gap detection). The purpose of the study was to evaluate behavioral and electrophysiological measures of within- and across-frequency temporal processing and their correlations with speech perception performance in CI users. Participants included 11 post-lingually deafened adult CI users (n = 15 ears; Mean Age = 50.2 yrs) and 11 age- and gender-matched normal hearing (NH) individuals (n = 15 ears; Mean Age = 49.0 yrs). Speech perception was assessed with Consonant-Nucleus-Consonant Word Recognition (CNC), Arizona Biomedical Sentence Recognition (AzBio), and Bamford-Kowal-Bench Speech-in-Noise Test (BKB-SIN) tests. Within- and across-frequency behavioral gap detection thresholds (referred to as the GDTwithin and GDTacross) were measured using an adaptive, two-alternative, forced-choice procedure. Cortical auditory evoked potentials (CAEPs) were elicited using within- and across-frequency gap stimuli under four gap duration conditions (no gap, GDT, sub-threshold GDT, and supra-threshold GDT). Correlations among speech perception, GDTs, and CAEPs were examined. CI users had poorer speech perception scores compared to NH listeners (p < 0.05), but the GDTs were not different between groups (p > 0.05). Compared to NH peers, CI users showed increased N1 latency in the CAEPs evoked by the across-frequency gap stimuli (p < 0.05). No group difference was observed for the CAEPs evoked by the within-frequency gap (p > 0.05). Three CI ears showing the longest GDTwithin also showed the poorest performance in speech in noise. The within-frequency CAEP increased in amplitude with the increase of gap duration; while the across-frequency CAEP displayed a similar amplitude for all gap durations. There was a significant correlation between speech scores and within-frequency CAEP measures for the supra-threshold GDT condition, with CI users with poorer speech performance having a smaller N1-P2 amplitude and longer N1 latency. No correlations were found among GDTacross, speech perception, and across-frequency CAEP measures. Within- and across-frequency gap detection may involve different neural mechanisms. The within-frequency gap detection task can help identify CI users with poor speech performance for rehabilitation. The within-frequency CAEP is a better predictor for speech perception performance than the across-frequency CAEP.

Cortical auditory evoked potential in cochlear implant users: An objective method to improve speech perception.

ObjectiveTo investigate if cortical auditory evoked potential (CAEP) measures can be used to verify the cochlear implant (CI) map and consequently improve CI outcomes in adults with bilateral hearing loss.DesignCAEPs were measured in CI recipients using the speech tokens /m/, /g/, /t/ and /s/. If CAEP responses were present for all speech tokens, the participant’s map was considered “satisfactory”. If CAEP responses were absent, the CI map was considered “unsatisfactory” and therefore adjusted and CAEP measures repeated. This was repeated until auditory potentials were seen in response to all four speech tokens. Speech testing was conducted pre-CI, as well as before and after CAEP-guided map adjustments.Results108 adult unilateral CI users participated, whose sound processors were previously programmed using subjective methods. 42 CI users elicited a CAEP response to all four speech tokens and therefore no further mapping adjustments were made. 66 subjected lacked a CAEP response to at least one speech token and had their CI map adjusted accordingly. Of those, 31 showed a CAEP response to all four speech tokens, and the average speech score significantly improved after CI map adjustments based on CAEP responses.ConclusionCAEP’s are an objective tool that can be used to guide and verify CI mapping in adults CI users. Significant improvement in speech scores was observed in participants who had their CI map adjusted based on CAEP responses.

Single-Sided Deafness: Emotional and Social Handicap, Impact on Health Status and Quality of Life, Functional Hearing, and the Effects of Cochlear Implantation.

To evaluate the functional and subjective outcomes in individuals with single-sided deafness (SSD) treated with a cochlear implant (CI). Eighty-one adult CI users with SSD participated in this study. Functional assessments consisted of speech in noise testing and localization. Subjective assessments consisted of the Speech Spatial Quality of Hearing Scale, the Tinnitus Reaction Questionnaire, the Abbreviated Profile of Hearing Aid Benefit questionnaire, the Hearing Handicap Inventory for Adults questionnaire, and the Glasgow Health Status Inventory and the Glasgow Benefit Inventory questionnaires. SSD has remarkable consequences on quality of life (QoL) and imposes a substantial emotional and social handicap on the individuals. Self-reported QoL improved after CI with tinnitus intrusion significantly reduced as early as 3 months post-CI. A significant improvement was seen in all speech understanding in noise configurations. Localization ability significantly improved with CI on. Our findings demonstrate that SSD reduces social and psychological QoL and imposes a remarkable level of handicap as per general and specific self-assessments tool. CI provided a significant improvement in function including speech understanding in noise and localization ability, as well as improved QoL and reduced tinnitus significantly in both the early and long terms.

Processing of linguistic and indexical information in adult cochlear implant users

Normal-hearing (NH) listeners simultaneously make use of both linguistic (speech content) and indexical (talker-specific) information in speech perception. For adult cochlear implant (CI) users, limitations in the talker-specific details conveyed by their devices may impact processing dependences between linguistic and indexical information. The current study examined the extent to which linguistic and indexical information are processed interdependently in adult CI users, using speeded phoneme and talker gender classification tasks. Higher-performing adult CI users (open-set word recognition &amp;gt;65% correct) reported the target vowel (phoneme classification) or target talker gender (gender classification). The non-target dimension varied by the number of talkers (phoneme classification) and the number of words (gender classification). Largely consistent with NH findings, adult CI users displayed asymmetric interference between linguistic and indexical dimensions. Phoneme classification was less accurate and slower with high talker variability. In contrast, gender classification was not affected by word variability. Processing dependencies also varied across individual CI users and related to auditory and cognitive-linguistic abilities. These preliminary findings suggest that adult CI users may make use of degraded linguistic and indexical information during speech processing. However, the extent to which they do so may depend on individual auditory and cognitive-linguistic factors.

Lexical effects on talker discrimination in adult cochlear implant users

The lexical and phonological content of an utterance impacts the processing of talker-specific details in normal-hearing (NH) listeners. For example, previous research has shown that NH listeners display stronger perception of talker-specific details for real words compared to nonwords, and for nonwords with high phonotactic probability compared to nonwords with low phonotactic probability. For adult cochlear implant (CI) users, limitations in the talker-specific details conveyed by their devices may alter the reliance on lexical information in talker discrimination. The current study examined the impact of lexical content on talker discrimination in adult CI users. In a same-different talker discrimination task, word pairs – produced either by the same or different talkers – were either lexically easy (high frequency, low neighborhood density) or lexically hard (low frequency, high neighborhood density). Results showed a significant interaction between lexical content and talker pair. For same-talker pairs, accuracy was higher for lexically easy words than lexically hard words. For different-talker pairs, accuracy was higher for lexically hard words than lexically easy words. Despite limitations in talker discrimination, these preliminary results suggest that adult CI users use lexical information in the processing of talker-specific details, and additionally may rely less on acoustic-phonetic details when processing is easy.

Differential relations of auditory and cognitive functions to speech recognition tasks in adult cochlear implant users

Clinical testing for assessing adult cochlear implant (CI) candidacy and outcomes relies primarily on tasks of open-set recognition for words and sentences. However, it is not clear in what ways performance on these different tasks relates differentially to auditory and cognitive functions. We tested the hypothesis that auditory and cognitive functions would contribute differentially to performance on recognition of isolated words (CID-W22 words), meaningful sentences (Harvard Standard), nonsense sentences (Harvard Anomalous), and sentences with high talker variability (PRESTO) in adult CI users. Sixty-five experienced CI users completed a battery of auditory and cognitive tests to assess auditory spectro-temporal processing, vocabulary size, working memory capacity, inhibition-concentration, nonverbal reasoning, and speed of lexical access. Findings were that spectro-temporal processing, lexical access speed, and nonverbal reasoning predicted scores across all word and sentence recognition tests. In contrast, inhibition-concentration contributed to nonsense sentence recognition, while vocabulary knowledge contributed to high talker variability sentence recognition. Results suggest that there is a core set of auditory and cognitive functions that contribute broadly to speech recognition, while more specific cognitive functions contribute to performance on some speech recognition tasks. Clinical implications are that individual cognitive abilities should be considered when evaluating CI candidacy and outcomes.

The Impact of the COVID-19 Lockdown on Quality of Life in Adult Cochlear Implant Users: A Survey Study.

Background: The COVID-19 pandemic rapidly spread through Europe in the first months of 2020. On the 9th of March 2020, the Italian government ordered a national lock-down. The study’s objectives were: to investigate the effect of lockdown on CI users; and to detect the difference in the perception of discomfort existing between unilateral cochlear implant (UCI) users and bilateral cochlear implant (BCI) users, due to the lockdown experience. Methods: A 17-item, web-based, anonymous online survey was administered to 57 CI users, exploring hearing performance, emotions, practical issues, behavior, and tinnitus. Participation in the study was voluntary. Results: all CI users obtained an abnormal score in all questionnaire themes. For the emotion theme and the practical issue theme, the age range 61–90 showed a significant difference between UCI and BCI users in favor of BCI users (emotion theme: UCI mean = 3.9, BCI mean = 2.3, p = 0.0138; practical issues: UCI mean = 4, BCI mean = 3, p = 0.0031). Conclusions: CI users experienced the lockdown negatively as regards behavior, emotions, hearing performance, and in practical issues. CI subjects with UCI in old age suffered more from the experience of lockdown than subjects with BCI in the same age, with regards to emotions and practical issues.