Bimodal speech perception in infant hearing aid and cochlear implant users

OBJECTIVES: To determine the feasibility of replicating prior bimodal perception findings with hearing-impaired infants during their preimplant, hearing aid trial, and postimplant experiences; secondarily, to determine the point in development at which these infants were able to match phonetic information in the lips and voice for the vowels /a/ and /i/. METHODS: A total of 10 infants with hearing loss, aged 4 to 24 months, were assessed at least once prior to cochlear implantation and previous to implant stimulation. The Split-Screen Preferential Looking Procedure was used to evaluate the bimodal perception skills of these infants. RESULTS: Examples of individual bimodal perception data and preliminary group data are presented. A difference in performance across preimplant and postimplant test sessions was noted for the individuals and the group. CONCLUSION: These data provide evidence that the infants' audibility levels were improved by their cochlear implants, which may have contributed to their evolving ability to match phonetic information in the lips and voice.     

Auditory/visual speech perception by cochlear implant users and hearing aid wearers

This study assessed the auditory/visual speech perception abilities of profoundly hearing-impaired subjects using the cochlear implant (CI) developed at the House Ear Institute with those of patients using traditional hearing aids (HA). Audio-video tape recordings of consonant-vowel-consonants (CVCs) consisting of: ten vowels in the context/mvm/, vowel-consonant-vowels (VCVs) consisting of twenty-four consonants in the context/ C /, and the CID Everyday Sentences were presented through auditory, visual, and auditory-visual modes. Subjects' verbal responses to the stimuli were transcribed by the experimenters. Statistical analyses of the data revealed significant differences for groups, stimuli, and conditions. Inspection of the subject's confusion matrices revealed that both groups used closed-bilabial, velar, dental, labial, and easy to see/hard to see features based on place of articulation in the visual mode. Salient features in the auditory mode for the CI group were duration, sonorancy, and some manner attributes, while the HA subjects used these features as well as sibilancy and voicing. Both groups integrated auditory and visual cues to improve scores in the auditory-visual condition. These findings have implications for future developments of auditory prostheses and auditory rehabilitation programs.     

Monosyllable speech perception of Japanese hearing aid users with prelingual hearing loss: implications for surgical indication of cochlear implant

OBJECTIVE: The monosyllable speech perception ability after years of educational intervention was compared between prelingually deafened pediatric hearing aid users and their cochlear implant counterparts. DESIGN: An open-set monosyllabic speech perception test was conducted on all subjects. The test required subjects to indicate a corresponding Japanese character to that spoken by the examiner. Fifty-two subjects with prelingual hearing impairment (47 hearing aid users and 5 cochlear implant users) were examined. RESULTS: Hearing aid users with average pure-tone thresholds less than 90 dB HL demonstrated generally better monosyllable perception than 70%, which was equivalent or better performance than that of the cochlear implant group. Widely dispersed speech perception was observed within the 90-99 dB HL hearing-aid user group with most subjects demonstrating less than 50% speech perception. In the cluster of >100 dB HL, few cases demonstrated more than 50% in speech perception. The perception ability of the vowel part of each mora within the cochlear implant group was 100% and corresponding to that of hearing aid users with moderate and severe hearing loss. CONCLUSION: Hearing ability among cochlear implant users can be comparable with that of hearing aid users with average unaided pure-tone thresholds of 90 dB HL, after monosyllabic speech perception testing was performed.     

Comparison of speech perception between monaural and binaural hearing in cochlear implant patients

Objective To assess the advantages of binaural hearing for cochlear implant (CI) users using a hearing aid (HA) for the contralateral ear.

Material and Methods The subjects comprised 3 males and 3 females (age range 48–84 years). All of them had been using a CI and HA for >6 months. Their speech perception was examined in quiet using monosyllables and Japanese Hearing in Noise Test (J-HINT) sentences. Speech perception in noise was examined using J-HINT sentences. Late cortical waves were measured while subjects listened to 1 kHz frequent and 2 kHz target tone stimuli. The latency of the event-related potential (P300) wave was compared for monaural and binaural hearing conditions.

Results Three subjects showed significantly better results for binaural than monaural (CI alone) hearing for monosyllables and HINT sentences (p<0.05; paired t-test). Subjects with better speech perception had been using an HA for longer than those with poor performance (18.3 vs 4.0 years). The overall average score was better for binaural than monaural hearing in the speech perception test under quiet and noisy conditions. Comparison of the latency of the P300 wave under monaural and binaural hearing conditions showed a significantly shorter latency for the latter (p=0.02; paired t-test).

Conclusion Although the use of an HA alone showed marginal benefit for CI users, binaural hearing (CI + HA) resulted in a significant improvement in speech perception under various circumstances.     

Comparison of speech perception between monaural and binaural hearing in cochlear implant patients

OBJECTIVE: To assess the advantages of binaural hearing for cochlear implant (CI) users using a hearing aid (HA) for the contralateral ear. MATERIAL AND METHODS: The subjects comprised 3 males and 3 females (age range 48-84 years). All of them had been using a CI and HA for > 6 months. Their speech perception was examined in quiet using monosyllables and Japanese Hearing in Noise Test (J-HINT) sentences. Speech perception in noise was examined using J-HINT sentences. Late cortical waves were measured while subjects listened to 1 kHz frequent and 2 kHz target tone stimuli. The latency of the event-related potential (P300) wave was compared for monaural and binaural hearing conditions. RESULTS: Three subjects showed significantly better results for binaural than monaural (CI alone) hearing for monosyllables and HINT sentences (p < 0.05; paired t-test). Subjects with better speech perception had been using an HA for longer than those with poor performance (18.3 vs 4.0 years). The overall average score was better for binaural than monaural hearing in the speech perception test under quiet and noisy conditions. Comparison of the latency of the P300 wave under monaural and binaural hearing conditions showed a significantly shorter latency for the latter (p = 0.02; paired t-test). CONCLUSIONS: Although the use of an HA alone showed marginal benefit for CI users, binaural hearing (CI+HA) resulted in a significant improvement in speech perception under various circumstances.     

Music perception of cochlear implant users compared with that of hearing aid users

OBJECTIVES: To investigate the music perception skills of adult cochlear implant (CI) users in comparison with hearing aid (HA) users who have similar levels of hearing impairment. It was hypothesized that the HA users would perform better than the CI recipients on tests involving pitch, instrument, and melody perception, but similarly for rhythm perception. DESIGN: Fifteen users of the Nucleus CI system and 15 HA users participated in a series of music perception tests. All subjects were postlingually deafened adults, with the HA subjects being required to meet the current audiological criteria for CI candidacy. A music test battery was designed for the study incorporating four major tasks: (1) discrimination of 38 pairs of rhythms; (2) pitch ranking of one-octave, half-octave, and quarter-octave intervals; (3) instrument recognition incorporating three subtests, each with 12 different instruments or ensembles; and (4) recognition of 10 familiar melodies. Stimuli were presented via direct audio input at comfortable presentation levels. The test battery was administered to each subject on two separate occasions, approximately 4 mo apart. RESULTS: The results from the rhythm test were 93% correct for the CI group and 94% correct for the HA group; these scores were not significantly different. For the pitch test, there was a significant difference between the HA group and the CI group (p < 0.001), with higher mean scores recorded by the HA group for all three interval sizes. The CI subject group was unable to rank pitches a quarter-octave apart, only scoring at chance level for this interval size. In the instrument recognition test, although there was no significant difference between the mean scores of the two groups, both groups obtained significantly higher scores for the subtest incorporating single instrument stimuli than those incorporating multiple instrumentations (p < 0.001). In the melody test, there was a significant difference between the implantees' mean score of 52% correct and the HA group's mean of 91% (p < 0.001). CONCLUSIONS: As hypothesized, results from the two groups were almost identical for the rhythm test, with the HA group performing significantly better than the CI group on the pitch and melody tests. However, there was no difference between the groups in their ability to identify musical instruments or ensembles. The results of this study indicate that HA users with similar levels of hearing loss perform at least equal to, if not better than, CI users on these music perception tests. However, despite the differences between scores obtained by the CI and HA subject groups, both these subject groups were largely unable to achieve accurate or effective music perception, regardless of the device they used.     

Binaural-bimodal hearing: concomitant use of a unilateral cochlear implant and a contralateral hearing aid

CONCLUSION: The benefit obtained with a contralateral hearing aid (HA) in unilateral cochlear implantees improves over time, at least during the first year after implantation. OBJECTIVE: To evaluate binaural-bimodal auditory ability and its early changes over time after unilateral cochlear implantation in patients with residual hearing in the non-implanted ear, in which they use an HA. MATERIAL AND METHODS: Sentence identification in background noise was tested in 12 patients (3 post-lingual adults and 9 pre-lingual adults and older children) under 3 listening conditions: cochlear implant (CI) alone, HA alone and CI+HA. The presentation level was 55 dB HL with a signal-to-noise ratio of +10 dB. Subjects were tested after 1-6 months of concomitant use of both devices and again after a further 7-12 months. RESULTS: At the first testing session, the mean score in background noise was 34.9% with CI alone (range 0-90%) and 41.1% with both devices (range 0-100%). Seven patients could recognize sentences in noise with CI alone, and four of them showed further improvement with added amplification. At the second session, at which all subjects could recognize sentences in noise with the CI alone, seven showed further improvement with added amplification. The mean score was 60.6% with CI alone (range 10-99%) and 75.5% with both devices (range 52-100%).     

Assessing speech recognition abilities with digits in noise in cochlear implant and hearing aid users

Objective: The primary objective of the study was to investigate the feasibility, reliability, and validity of the Dutch digits in noise (DIN) test for measuring speech recognition in hearing aid and cochlear implant users and compare results to the standard sentences-in-noise (SIN) test. Design: The relation between speech reception thresholds for DIN test and SIN test was analysed to determine the validity of the DIN test. As linguistic skills were expected to make different contributions in these tests, their influence was analysed. Study sample: Participants were 12 normal-hearing listeners, 24 hearing aid users, and 24 cochlear implant users. Results: The DIN test was feasible for more participants than the SIN test. Intraclass correlation coefficients showed high reliability. The standard error of measurement was smaller for the DIN test than for the SIN test. DIN test and SIN test were highly correlated (r = 0.95 and r = 0.56 for NH+ HA and CI users respectively). In the regression analysis no significant contribution of basic linguistic skills or personal factors was found. Conclusion: In the assessment of speech recognition in noise of aided hearing-impaired listeners with hearing aids or cochlear implants, the DIN test is a feasible, reliable and valid test.     

Speech perception with a cochlear implant used in conjunction with a hearing aid in the opposite ear

The aim of this study was to determine the improvement in speech recognition provided by a cochlear implant (CI) in conjunction with a hearing aid (HA) in the opposite ear. The study was a retrospective cohort study in the context of a university teaching hospital CI programme. Seven CI patients who still use their HA in the opposite ear were tested. The scores with the CI alone and the CI in conjunction with an HA were evaluated by using three speech perception tests in quiet (Freiburger Numbers. Freiburger Monosyllables, and Innsbrucker Sentence Test). In the majority of tests and subjects. the CI alone performed better than the HA alone, and the bimodal (CI + HA) condition was superior to the CI alone. On the sentence test, the patients as a group improved from 47 96% (mean: 79%; CI alone) to 50-100% (mean: 88.1%; CI + HA, pv < 0.05). With the more difficult monosyllable test, the scores improved from 15-52% (mean: 37.2%; CI alone) to 15 82% (mean: 48.7%; CI + HA, p < 0.05). On the numbers test. scores increased from 65-98% (mean: 83%; CI alone) to 75-98% (mean: 88.7%; CI + HA, p < 0.05). All patients in this study were implanted in the poorer ear. The results of the present study suggest the advantage of CI usage in conjunction with an HA in the opposite ear.     

Speech perception with a cochlear implant used in conjunction with a hearing aid in the opposite ear

The aim of this study was to determine the improvement in speech recognition provided by a cochlear implant (CI) in conjunction with a hearing aid (HA) in the opposite ear. The study was a retrospective cohort study in the context of a university teaching hospital CI programme. Seven CI patients who still use their HA in the opposite ear were tested. The scores with the CI alone and the CI in conjunction with an HA were evaluated by using three speech perception tests in quiet (Freiburger Numbers, Freiburger Monosyllables, and Innsbrucker Sentence Test). In the majority of tests and subjects, the CI alone performed better than the HA alone, and the bimodal (CI+HA) condition was superior to the CI alone. On the sentence test, the patients as a group improved from 47-96% (mean: 79%; CI alone) to 50-100% (mean: 88.1%; CI+HA, pv<0.05). With the more difficult monosyllable test, the scores improved from 15-52% (mean: 37.2%; CI alone) to 15-82% (mean: 48.7%; CI+ HA, p<0.05). On the numbers test, scores increased from 65-98% (mean: 83%; CI alone) to 75-98% (mean: 88.7%; CI+ HA, p<0.05). All patients in this study were implanted in the poorer ear. The results of the present study suggest the advantage of CI usage in conjunction with an HA in the opposite ear.     

人工耳蜗与助听器有何不同?

人工耳蜗又称电子耳蜗，是一种模拟耳蜗功能的声-电换能装置，它可以帮助患有重度或极重度耳聋的小儿和成人重建听力、获得听觉。     

Audiovisual speech perception in elderly cochlear implant recipients

OBJECTIVES/HYPOTHESIS: This study examined the speech perception skills of a younger and older group of cochlear implant recipients to determine the benefit that auditory and visual information provides for speech understanding. STUDY DESIGN: Retrospective review. METHODS: Pre- and postimplantation speech perception scores from the Consonant-Nucleus-Consonant (CNC), the Hearing In Noise sentence Test (HINT), and the City University of New York (CUNY) tests were analyzed for 34 postlingually deafened adult cochlear implant recipients. Half were elderly (i.e., >65 y old) and other half were middle aged (i.e., 39-53 y old). The CNC and HINT tests were administered using auditory-only presentation; the CUNY test was administered using auditory-only, vision-only, and audiovisual presentation conditions RESULTS: No differences were observed between the two age groups on the CNC and HINT tests. For a subset of individuals tested with the CUNY sentences, we found that the preimplantation speechreading scores of the younger group correlated negatively with auditory-only postimplant performance. Additionally, older individuals demonstrated a greater reliance on the integration of auditory and visual information to understand sentences than did the younger group CONCLUSIONS: On average, the auditory-only speech perception performance of older cochlear implant recipients was similar to the performance of younger adults. However, variability in speech perception abilities was observed within and between both age groups. Differences in speechreading skills between the younger and older individuals suggest that visual speech information is processed in a different manner for elderly individuals than it is for younger adult cochlear implant recipients.     

Spectral and temporal cues in cochlear implant speech perception

OBJECTIVE: Taking advantage of the flexibility in the number of stimulating electrodes and the stimulation rate in a modern cochlear implant, the present study evaluated relative contributions of spectral and temporal cues to cochlear implant speech perception. DESIGN: Four experiments were conducted by using a Research Interface Box in five MED-EL COMBI 40+ cochlear implant users. Experiment 1 varied the number of electrodes from four to twelve or the maximal number of available active electrodes while keeping a constant stimulation rate at 1000 Hz per electrode. Experiment 2 varied the stimulation rate from 1000 to 4000 Hz per electrode on four pairs of fixed electrodes. Experiment 3 covaried the number of stimulating electrodes and the stimulation rate to study the trade-off between spectral and temporal cues. Experiment 4 studied the effects of envelope extraction on speech perception and listening preference, including half-wave rectification, full-wave rectification, and the Hilbert transform. Vowels, consonants, and HINT sentences in quiet, as well as with a competing female voice served as test materials. RESULTS: Experiment 1 found significant improvement in all speech tests with a higher number of stimulating electrodes. Experiment 2 found a significant advantage of the high stimulation rate only on consonant recognition and sentence recognition in noise. Experiment 3 found an almost linear trade-off between the number of stimulation electrodes and the stimulation rate for consonant and sentence recognition in quiet, but not for vowel and sentence recognition in noise. Experiment 4 found significantly better performance with the Hilbert transform and the full-wave rectification than the half-wave rectification. In addition, envelope extraction with the Hilbert transform produced the highest rating on subjective judgment of sound quality. CONCLUSIONS: Consistent with previous studies, the present result from the five MED-EL subjects showed that (1) the temporal envelope cues from a limited number of channels are sufficient to support high levels of phoneme and sentence recognition in quiet but not for speech recognition in a competing voice, (2) consonant recognition relies more on temporal cues while vowel recognition relies more on spectral cues, (3) spectral and temporal cues can be traded to some degree to produce similar performance in cochlear implant speech recognition, and (4) the Hilbert envelope improves both speech intelligibility and quality in cochlear implants.     

Production and perception of speech intonation in pediatric cochlear implant recipients and individuals with normal hearing

OBJECTIVES: Current cochlear implant (CI) devices are limited in providing voice pitch information that is critical for listeners' recognition of prosodic contrasts of speech (e.g., intonation and lexical tones). As a result, mastery of the production and perception of such speech contrasts can be very challenging for prelingually deafened individuals who received a CI in their childhood (i.e., pediatric CI recipients). The purpose of this study was to investigate (a) pediatric CI recipients' mastery of the production and perception of speech intonation contrasts, in comparison with their age-matched peers with normal hearing (NH), and (b) the relationships between intonation production and perception in CI and NH individuals. DESIGN: Twenty-six pediatric CI recipients aged from 7.44 to 20.74 yrs and 17 age-matched individuals with NH participated. All CI users were prelingually deafened, and each of them received a CI between 1.48 and 6.34 yrs of age. Each participant performed an intonation production task and an intonation perception task. In the production task, 10 questions and 10 statements that were syntactically matched (e.g., "The girl is on the playground." versus "The girl is on the playground?") were elicited from each participant using interactive discourse involving pictures. These utterances were judged by a panel of eight adult listeners with NH in terms of utterance type accuracy (question versus statement) and contour appropriateness (on a five-point scale). In the perception task, each participant identified the speech intonation contrasts of natural utterances in a two-alternative forced-choice task. RESULTS: The results from the production task indicated that CI participants' scores for both utterance type accuracy and contour appropriateness were significantly lower than the scores of NH participants (both p < 0.001). The results from the perception task indicated that CI participants' identification accuracy was significantly lower than that of their NH peers (CI, 70.13% versus NH, 97.11%, p < 0.001). The Pearson correlation coefficients (r) between CI participants' performance levels in the production and perception tasks were approximately 0.65 (p = 0.001). CONCLUSION: As a group, pediatric CI recipients do not show mastery of speech intonation in their production or perception to the same extent as their NH peers. Pediatric CI recipients' performance levels in the production and perception of speech intonation contrasts are moderately correlated. Intersubject variability exists in pediatric CI recipients' mastery levels in the production and perception of speech intonation contrasts. These findings suggest the importance of addressing both aspects (production and perception) of speech intonation in the aural rehabilitation and speech intervention programs for prelingually deafened children and young adults who use a CI.     

The mechanism of speech perception using multichannel cochlear implant

The mechanism of speech perception in patients with Australian multi-channel cochlear implant was investigated. 1) Vowel recognition abilities of patients were sufficient with this implant, whereas, consonant recognition abilities were insufficient. 2) Although the cochlear hair cells were functionally damaged, cochlear nerves had the ability to characterize frequency. 3) The signals from the implanted material were very simple compared to those from normal cochlea, however these patients could understand speech well, perhaps due to aid from the central nervous system.