 |
|
|
|
| |
Auditory Training for Cochelar Implant Recipients
Feasibility, Outcomes, and Future Directions
Here lists the recent development of auditory training studies.
- 2007-Perceptual Learning and Auditory Training in Cochlear Implant Recipients
- 2007-Computer-Assisted Speech Training for Cochlear Implant Patients: Feasibility, Outcomes, and Future Directions
- 2007-Melodic Contour Identification by Cochlear Implant Listeners.
- 2007-Effects of Computer-Assisted Speech Training on Mandarin-Speaking Hearing-Impaired Children
- 2007-Perceptual Adaptation to Spectrally Shifted Vowels: Training with Nonlexical Labels
- 2007-The effect of training rate on recognition of spectrally shifted speech
- 2005-Moderate auditory training can improve speech performance of adults cochlear implant patients.
- 2005-Auditory training with spectrally shifted speech: an implication for cochlear implant users’ auditory rehabilitation.
- 2003-The effects of short-term training for spectrally mismatched noise-band speech
Perceptual Learning and Auditory Training in Cochlear Implant Recipients
Learning electrically stimulated speech patterns can be a new and difficult experience for cochlear implant (CI) recipients. Recent studies have shown that most implant recipients at least partially adapt to these new patterns via passive, daily-listening experiences. Gradually introducing a speech processor parameter (eg, the degree of spectral mismatch) may provide for more complete and less stressful adaptation. Although the implant device restores hearing sensation and the continued use of the implant provides some degree of adaptation, active auditory rehabilitation may be necessary to maximize the benefit of implantation for CI recipients. Currently, there are scant resources for auditory rehabilitation for adult, postlingually deafened CI recipients. We recently developed a computer-assisted speech-training program to provide the means to conduct auditory rehabilitation at home. The training software targets important acoustic contrasts among speech stimuli, provides auditory and visual feedback, and incorporates progressive training techniques, thereby maintaining recipients' interest during the auditory training exercises. Our recent studies demonstrate the effectiveness of targeted auditory training in improving CI recipients' speech and music perception. Provided with an inexpensive and effective auditory training program, CI recipients may find the motivation and momentum to get the most from the implant device.
Computer-Assisted Speech Training for Cochlear Implant Patients: Feasibility, Outcomes, and Future Directions
Semin Hear 2007; 28: 142-150; DOI: 10.1055/s-2007-973440
Learning electrically stimulated speech patterns can be a new and difficult experience for cochlear implant patients. Cochlear implantation alone may not fully meet the needs of many patients, and additional auditory rehabilitation may be necessary to maximize the benefits of the implanted device. A recently developed computer-assisted speech-training program provides cochlear implant patients with the means to conduct auditory rehabilitation at home. The training software targets important acoustic contrasts between speech stimuli and provides auditory and visual feedback as well as progressive training, thereby maintaining patients' interest in the auditory training exercises. Recent scientific studies have demonstrated the effectiveness of such specialized auditory training programs in improving cochlear implant patients' speech recognition performance. Provided with an inexpensive and accessible auditory training program, cochlear implant patients may find the motivation and momentum to get the most from the implanted device.
Melodic Contour Identification by Cochlear Implant Listeners.
Ear & Hearing. 28(3):302-319, June 2007.
Abstract:
Objective: While the cochlear implant provides many deaf patients with good speech understanding in quiet, music perception and appreciation with the cochlear implant remains a major challenge for most cochlear implant users. The present study investigated whether a closed-set melodic contour identification (MCI) task could be used to quantify cochlear implant users' ability to recognize musical melodies and whether MCI performance could be improved with moderate auditory training. The present study also compared MCI performance with familiar melody identification (FMI) performance, with and without MCI training. Methods: For the MCI task, test stimuli were melodic contours composed of 5 notes of equal duration whose frequencies corresponded to musical intervals. The interval between successive notes in each contour was varied between 1 and 5 semitones; the "root note" of the contours was also varied (A3, A4, and A5). Nine distinct musical patterns were generated for each interval and root note condition, resulting in a total of 135 musical contours. The identification of these melodic contours was measured in 11 cochlear implant users. FMI was also evaluated in the same subjects; recognition of 12 familiar melodies was tested with and without rhythm cues. MCI was also trained in 6 subjects, using custom software and melodic contours presented in a different frequency range from that used for testing. Results: Results showed that MCI recognition performance was highly variable among cochlear implant users, ranging from 14% to 91% correct. For most subjects, MCI performance improved as the number of semitones between successive notes was increased; performance was slightly lower for the A3 root note condition. Mean FMI performance was 58% correct when rhythm cues were preserved and 29% correct when rhythm cues were removed. Statistical analyses revealed no significant correlation between MCI performance and FMI performance (with or without rhythmic cues). However, MCI performance was significantly correlated with vowel recognition performance; FMI performance was not correlated with cochlear implant subjects' phoneme recognition performance. Preliminary results also showed that the MCI training improved all subjects' MCI performance; the improved MCI performance also generalized to improved FMI performance. Conclusions: Preliminary data indicate that the closed-set MCI task is a viable approach toward quantifying an important component of cochlear implant users' music perception. The improvement in MCI performance and generalization to FMI performance with training suggests that MCI training may be useful for improving cochlear implant users' music perception and appreciation; such training may be necessary to properly evaluate patient performance, as acute measures may underestimate the amount of musical information transmitted by the cochlear implant device and received by cochlear implant listeners.
Effects of Computer-Assisted Speech Training on Mandarin-Speaking Hearing-Impaired Children
Audiol Neurotol 2007;12:307-312 (DOI:10.1159/000103211)
The present study investigated whether moderate amounts of computer-assisted speech training can improve the speech recognition performance of hearing-impaired children. Ten Mandarin-speaking children (3 hearing aid users and 7 cochlear implant users) participated in the study. Training was conducted at home using a personal computer for half an hour per day, 5 days per week, for a period of 10 weeks. Results showed significant improvements in subjects' vowel, consonant, and tone recognition performance after training. The improved performance was largely retained for 2 months after training was completed. These results suggest that moderate amounts of auditory training, using a computer-based auditory rehabilitation tool with minimal supervision, can be effective in improving the speech performance of hearing-impaired children.
Perceptual Adaptation to Spectrally Shifted Vowels: Training with Nonlexical Labels
Although normal-hearing (NH) and cochlear implant (CI) listeners are able to adapt to spectrally shifted speech to some degree, auditory training has been shown to provide more complete and/or accelerated adaptation. However, it is unclear whether listeners use auditory and visual feedback to improve discrimination of speech stimuli, or to learn the identity of speech stimuli. The present study investigated the effects of training with lexical and nonlexical labels on NH listeners' perceptual adaptation to spectrally degraded and spectrally shifted vowels. An eight-channel sine wave vocoder was used to simulate CI speech processing. Two degrees of spectral shift (moderate and severe shift) were studied with three training paradigms, including training with lexical labels (i.e., “hayed,” “had,” “who'd,” etc.), training with nonlexical labels (i.e., randomly assigned letters “f,” “b,” “g,” etc.), and repeated testing with lexical labels (i.e., “test-only” paradigm without feedback). All training and testing was conducted over 5 consecutive days, with two to four training exercises per day. Results showed that with the test-only paradigm, lexically labeled vowel recognition significantly improved for moderately shifted vowels; however, there was no significant improvement for severely shifted vowels. Training with nonlexical labels significantly improved the recognition of nonlexically labeled vowels for both shift conditions; however, this improvement failed to generalize to lexically labeled vowel recognition with severely shifted vowels. Training with lexical labels significantly improved lexically labeled vowel recognition with severely shifted vowels. These results suggest that storage and retrieval of speech patterns in the central nervous system is somewhat robust to tonotopic distortion and spectral degradation. Although training with nonlexical labels may improve discrimination of spectrally distorted peripheral patterns, lexically meaningful feedback is needed to identify these peripheral patterns. The results also suggest that training with lexically meaningful feedback may be beneficial to CI users, especially patients with shallow electrode insertion depths.
The effect of training rate on recognition of spectrally shifted speech
Ear & Hearing. 28(2):132-140, April 2007.
OBJECTIVE: Previous studies have shown that the protocol used for auditory training may significantly affect the outcome of training. However, it is unclear how often training should be performed to maximize its benefit. The present study investigated how the frequency of training contributed to normal-hearing listeners’ adaptation to spectrally shifted speech. METHODS: Eighteen normal-hearing listeners were trained with spectrally shifted and compressed speech via an 8-channel acoustic simulation of cochlear implant speech processing. Five short training sessions (1 hour per session) were completed by each subject; subjects were trained at one of three training rates: 5 sessions per week, 3 sessions per week or 1 session per week. Subjects were trained to identify medial vowels presented in a cVc format; depending on the level of difficulty, the number of response choices was increased and/or the acoustic differences between vowels were reduced. Vowel and consonant recognition was measured before and after training, as well as at regular intervals during the training period. Sentence recognition was measured before and after training only. RESULTS: Results showed that pre-training vowel recognition scores were poor (14.0 % correct, on average) for all subjects, due to the severe spectral shift. After five sessions of targeted vowel contrast training, there was a significant improvement of shifted vowel recognition for most subjects. The mean improvement was comparable (~ 15 percentage points) across the three training rate conditions, despite significant inter-subject variability in pre- and post-training baseline performance. There was no significant difference in training outcomes among the three training rates. Spectrally shifted consonant and sentence recognition also improved by ~ 20 percentage points after training, even though consonants and sentences were not explicitly trained. Similar to vowel recognition, there was no significant difference in training outcomes among the three training rates for shifted consonant and sentence recognition. CONCLUSION: The results demonstrated that the training rate had little effect on normal-hearing listeners’ adaptation to spectrally shifted speech, at least for the training periods (ranging from one to five weeks) used in the present study. The outcome of auditory training may depend more strongly on the amount of training (i.e., total number of training sessions), rather than the frequency of training (i.e., daily or once a week). While more frequent training may accelerate listeners’ adaptation to spectrally shifted speech, there may be significant benefits from training as little as one session per week. The results of the present study suggest that appropriate training schedules can be developed to optimize the effectiveness, efficiency and effort associated with hearing-impaired patients’ auditory rehabilitation.
Moderate auditory training can improve speech performance of adult cochlear implant patients
(Acoustics Research Letters Online -- July 2005, Volume 6, Issue 3, pp. 106-111)
Learning electrically stimulated speech patterns can be a new and difficult experience for many cochlear implant users. In the present study, ten cochlear implant patients participated in an auditory training program using speech stimuli. Training was conducted at home using a personal computer for 1 hour per day, 5 days per week, for a period of 1 month or longer. Results showed a significant improvement in all patients’ speech perception performance. These results suggest that moderate auditory training using a computer-based auditory rehabilitation tool can be an effective approach for improving the speech perception performance of cochlear implant patients.
Auditory training with spectrally shifted speech: implications for cochlear implant patient auditory rehabilitation
(Journal of the Association for Research in Otolaryngology, Volume 6, Number 2, Pages: 180 - 189)
After implantation, post-lingually deafened cochlear implant patients must adapt to both spectrally-reduced and spectrally-shifted speech, due to the limited number of electrodes and the limited length of the electrode array. This adaptation generally occurs during the first 3-6 months of implant use and may continue for many years. To see whether moderate speech training can accelerate this learning process, 16 naïve, normal-hearing listeners were trained with spectrally shifted speech via an 8-channel acoustic simulation of cochlear implant speech processing. Baseline vowel and consonant recognition was measured for both spectrally shifted and unshifted speech. Short daily training sessions were conducted over 5 consecutive days, using 4 different protocols. For the test-only protocol, no improvement was seen over the 5-day period. Similarly, sentence training provided little benefit for vowel recognition. However, after 5 days of targeted phoneme training, subjects’ recognition of spectrally shifted vowels significantly improved in most subjects. This improvement did not generalize to the spectrally unshifted vowel and consonant tokens, suggesting that subjects adapted to the specific spectral shift, rather than to the 8-channel processing in general. Interestingly, significant improvement was also observed for the recognition of spectrally shifted consonants. The largest improvement was observed with targeted vowel contrast training, which did not include any explicit consonant training. These results suggest that targeted phoneme training can accelerate adaptation to spectrally shifted speech. Given these results with normal-hearing listeners, auditory rehabilitation tools that provide targeted phoneme training may be effective in improving the speech recognition performance of adult cochlear implant users.
The effects of short-term training for spectrally mismatched noise-band speech
The present study examined the effects of short-term perceptual training on normal-hearing listeners' ability to adapt to spectrally altered speech patterns. Using noise-band vocoder processing, acoustic information was spectrally distorted by shifting speech information from one frequency region to another. Six subjects were tested with spectrally shifted sentences after five days of practice with upwardly shifted training sentences. Training with upwardly shifted sentences significantly improved recognition of upwardly shifted speech; recognition of downwardly shifted speech was nearly unchanged. Three subjects were later trained with downwardly shifted speech. Results showed that the mean improvement was comparable to that observed with the upwardly shifted training. In this retrain and retest condition, performance was largely unchanged for upwardly shifted sentence recognition, suggesting that these listeners had retained some of the improved speech perception resulting from the previous training. The results suggest that listeners are able to partially adapt to a spectral shift in acoustic speech patterns over the short-term, given sufficient training. However, the improvement was localized to where the spectral shift was trained, as no change in performance was observed for spectrally altered speech outside of the trained regions.
