Effects of Chronic Electrical Stimulation on Patients using a Cochlear Prosthesis

1991 ◽  
Vol 105 (6) ◽  
pp. 797-801 ◽  
Author(s):  
Susan B. Waltzman ◽  
Noel L. Cohen ◽  
William H. Shapiro
Keyword(s):  
Electrical Stimulation ◽  
Speech Recognition ◽  
Cochlear Implant ◽  
Dynamic Range ◽  
Cochlear Prosthesis ◽  
Postoperative Performance ◽  
Open Set ◽  
Chronic Electrical Stimulation

Eighteen patients using the Nucleus multichannel cochlear prosthesis underwent annual evaluations for electrical thresholds, dynamic range, and speech recognition abilities for a period of 1 to 5 years. Results revealed no correlation between length of usage of a cochlear implant and electrical thresholds. The dynamic range was initially wider in the patients with open-set speech recognition, but narrowed in subsequent years. There was a correlation between length of deafness and postoperative performance.

Efficacy of a Cochlear Implant Simultaneous Analog Stimulation Strategy Coupled with a Monopolar Electrode Configuration

2005 ◽  
Vol 114 (11) ◽  
pp. 886-893 ◽  
Author(s):  
Li Xu ◽  
Teresa A. Zwolan ◽  
Catherine S. Thompson ◽  
Bryan E. Pfingst
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Speech Processing ◽  
Dynamic Range ◽  
Recognition Performance ◽  
Electrode Configuration ◽  
Processing Strategy ◽  
Open Set ◽  
Hearing In Noise ◽  
Noise Test

Objectives: The present study was performed to evaluate the efficacy and clinical feasibility of using monopolar stimulation with the Clarion Simultaneous Analog Stimulation (SAS) strategy in patients with cochlear implants. Methods: Speech recognition by 10 Clarion cochlear implant users was evaluated by means of 4 different speech processing strategy/electrode configuration combinations; ie, SAS and Continuous Interleaved Sampling (CIS) strategies were each used with monopolar (MP) and bipolar (BP) electrode configurations. The test measures included consonants, vowels, consonant-nucleus-consonant words, and Hearing in Noise Test sentences with a +10 dB signal-to-noise ratio. Additionally, subjective judgments of sound quality were obtained for each strategy/configuration combination. Results: All subjects but 1 demonstrated open-set speech recognition with the SAS/MP combination. The group mean Hearing in Noise Test sentence score for the SAS/MP combination was 31.6% (range, 0% to 92%) correct, as compared to 25.0%, 46.7%, and 37.8% correct for the CIS/BP, CIS/MP, and SAS/BP combinations, respectively. Intersubject variability was high, and there were no significant differences in mean speech recognition scores or mean preference ratings among the 4 strategy/configuration combinations tested. Individually, the best speech recognition performance was with the subject's everyday strategy/configuration combination in 72% of the applicable cases. If the everyday strategy was excluded from the analysis, the subjects performed best with the SAS/MP combination in 37.5% of the remaining cases. Conclusions: The SAS processing strategy with an MP electrode configuration gave reasonable speech recognition in most subjects, even though subjects had minimal previous experience with this strategy/configuration combination. The SAS/MP combination might be particularly appropriate for patients for whom a full dynamic range of electrical hearing could not be achieved with a BP configuration.

Effect of Speech Processor Program Modifications on Cochlear Implant Recipients’ Threshold and Maximum Acceptable Loudness Levels

1999 ◽  
Vol 8 (2) ◽  
pp. 128-136 ◽  
Author(s):  
John C. Sun ◽  
Margarate W. Skinner ◽  
S. Y. Liu ◽  
T. S. Huang
Keyword(s):  
Electrical Stimulation ◽  
Cochlear Implant ◽  
Everyday Life ◽  
Dynamic Range ◽  
Active Electrode ◽  
Speech Processor ◽  
Significant Change ◽  
Upper Boundary

This study’s purpose was to determine whether or not modifications in speech processor electrical stimulation levels were associated with changes in five Nucleus 22 cochlear implant recipients’ thresholds or maximum acceptable loudness levels (MALs). These modifications in minimum and maximum stimulation levels were made to optimize hearing in everyday life. One threshold and one MAL were obtained on each active electrode during six, weekly test sessions, three before and three after program modification. Only one participant had a significant change in threshold after program modification; this participant and four others had significant changes in MAL. Participants’ threshold variability was the same, but MAL variability was higher than that observed in other studies. Because these participants had no experience making MAL judgments prior to this study, this result suggests that implant recipients should be given sufficient practice in making MAL judgments to provide a stable clinical estimate of the upper boundary of the electrical dynamic range.

Evaluation of Automatic Directional Processing with Cochlear Implant Recipients

2021 ◽  
Vol 32 (08) ◽  
pp. 478-486
Author(s):  
Lisa G. Potts ◽  
Soo Jang ◽  
Cory L. Hillis
Keyword(s):  
Signal Processing ◽  
Speech Recognition ◽  
Cochlear Implant ◽  
Mixed Model ◽  
Dynamic Range ◽  
Individual Variability ◽  
Noise Performance ◽  
Mixed Model Analysis ◽  
Speech In Noise ◽  
Speech Recognition In Noise

Abstract Background For cochlear implant (CI) recipients, speech recognition in noise is consistently poorer compared with recognition in quiet. Directional processing improves performance in noise and can be automatically activated based on acoustic scene analysis. The use of adaptive directionality with CI recipients is new and has not been investigated thoroughly, especially utilizing the recipients' preferred everyday signal processing, dynamic range, and/or noise reduction. Purpose This study utilized CI recipients' preferred everyday signal processing to evaluate four directional microphone options in a noisy environment to determine which option provides the best speech recognition in noise. A greater understanding of automatic directionality could ultimately improve CI recipients' speech-in-noise performance and better guide clinicians in programming. Study Sample Twenty-six unilateral and seven bilateral CI recipients with a mean age of 66 years and approximately 4 years of CI experience were included. Data Collection and Analysis Speech-in-noise performance was measured using eight loudspeakers in a 360-degree array with HINT sentences presented in restaurant noise. Four directional options were evaluated (automatic [SCAN], adaptive [Beam], fixed [Zoom], and Omni-directional) with participants' everyday use signal processing options active. A mixed-model analysis of variance (ANOVA) and pairwise comparisons were performed. Results Automatic directionality (SCAN) resulted in the best speech-in-noise performance, although not significantly better than Beam. Omni-directional performance was significantly poorer compared with the three other directional options. A varied number of participants performed their best with each of the four-directional options, with 16 performing best with automatic directionality. The majority of participants did not perform best with their everyday directional option. Conclusion The individual variability seen in this study suggests that CI recipients try with different directional options to find their ideal program. However, based on a CI recipient's motivation to try different programs, automatic directionality is an appropriate everyday processing option.

Experimental Basis and Design of a New Cochlear Prosthesis System

1987 ◽  
Vol 96 (1_suppl) ◽  
pp. 76-79
Author(s):  
J. Génin ◽  
R. Charachon
Keyword(s):  
Theoretical Model ◽  
Integrated Circuits ◽  
Cochlear Implant ◽  
Dynamic Range ◽  
Complementary Metal Oxide Semiconductor ◽  
Metal Oxide Semiconductor ◽  
Oxide Semiconductor ◽  
Semiconductor Technology ◽  
Experimental Basis ◽  
Cochlear Prosthesis

In a multichannel cochlear prosthesis, electrical interactions between electrodes impose severe limitations on dynamic range and selectivity. We present a theoretical model to cope with these limitations. Building a successful cochlear implant requires full custom-integrated circuits. We present the design of such a device, implemented in complementary metal oxide semiconductor technology. The area of the chip is 9 mm2 and it can stimulate 15 cochlear electrodes with current impulses.

scholarly journals Recognition and Localization of Speech by Adult Cochlear Implant Recipients Wearing a Digital Hearing Aid in the Nonimplanted Ear (Bimodal Hearing)

2009 ◽  
Vol 20 (06) ◽  
pp. 353-373 ◽  
Author(s):  
Lisa G. Potts ◽  
Margaret W. Skinner ◽  
Ruth A. Litovsky ◽  
Michael J. Strube ◽  
Francis Kuk
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Repeated Measures ◽  
Dynamic Range ◽  
Hearing Aid ◽  
Bilateral Stimulation ◽  
Bimodal Condition ◽  
Digital Hearing Aid ◽  
Loudness Growth ◽  
Bimodal Hearing

Background: The use of bilateral amplification is now common clinical practice for hearing aid users but not for cochlear implant recipients. In the past, most cochlear implant recipients were implanted in one ear and wore only a monaural cochlear implant processor. There has been recent interest in benefits arising from bilateral stimulation that may be present for cochlear implant recipients. One option for bilateral stimulation is the use of a cochlear implant in one ear and a hearing aid in the opposite nonimplanted ear (bimodal hearing). Purpose: This study evaluated the effect of wearing a cochlear implant in one ear and a digital hearing aid in the opposite ear on speech recognition and localization. Research Design: A repeated-measures correlational study was completed. Study Sample: Nineteen adult Cochlear Nucleus 24 implant recipients participated in the study. Intervention: The participants were fit with a Widex Senso Vita 38 hearing aid to achieve maximum audibility and comfort within their dynamic range. Data Collection and Analysis: Soundfield thresholds, loudness growth, speech recognition, localization, and subjective questionnaires were obtained six–eight weeks after the hearing aid fitting. Testing was completed in three conditions: hearing aid only, cochlear implant only, and cochlear implant and hearing aid (bimodal). All tests were repeated four weeks after the first test session. Repeated-measures analysis of variance was used to analyze the data. Significant effects were further examined using pairwise comparison of means or in the case of continuous moderators, regression analyses. The speech-recognition and localization tasks were unique, in that a speech stimulus presented from a variety of roaming azimuths (140 degree loudspeaker array) was used. Results: Performance in the bimodal condition was significantly better for speech recognition and localization compared to the cochlear implant–only and hearing aid–only conditions. Performance was also different between these conditions when the location (i.e., side of the loudspeaker array that presented the word) was analyzed. In the bimodal condition, the speech-recognition and localization tasks were equal regardless of which side of the loudspeaker array presented the word, while performance was significantly poorer for the monaural conditions (hearing aid only and cochlear implant only) when the words were presented on the side with no stimulation. Binaural loudness summation of 1–3 dB was seen in soundfield thresholds and loudness growth in the bimodal condition. Measures of the audibility of sound with the hearing aid, including unaided thresholds, soundfield thresholds, and the Speech Intelligibility Index, were significant moderators of speech recognition and localization. Based on the questionnaire responses, participants showed a strong preference for bimodal stimulation. Conclusions: These findings suggest that a well-fit digital hearing aid worn in conjunction with a cochlear implant is beneficial to speech recognition and localization. The dynamic test procedures used in this study illustrate the importance of bilateral hearing for locating, identifying, and switching attention between multiple speakers. It is recommended that unilateral cochlear implant recipients, with measurable unaided hearing thresholds, be fit with a hearing aid.

Speech Perception Performance in Experienced Cochlear-Implant Patients Receiving the SPEAK Processing Strategy in the Nucleus Spectra-22 Cochlear Implant

1998 ◽  
Vol 41 (5) ◽  
pp. 1073-1087 ◽  
Author(s):  
Aaron J. Parkinson ◽  
Wendy S. Parkinson ◽  
Richard S. Tyler ◽  
Mary W. Lowder ◽  
Bruce J. Gantz
Keyword(s):  
Speech Recognition ◽  
Speech Perception ◽  
Cochlear Implant ◽  
Sound Quality ◽  
Learning Effects ◽  
Processing Strategy ◽  
Subjective Ratings ◽  
Open Set ◽  
Wide Range

Sixteen experienced cochlear implant patients with a wide range of speechperception abilities received the SPEAK processing strategy in the Nucleus Spectra-22 cochlear implant. Speech perception was assessed in quiet and in noise with SPEAK and with the patients' previous strategies (for most, Multipeak) at the study onset, as well as after using SPEAK for 6 months. Comparisons were made within and across the two test sessions to elucidate possible learning effects. Patients were also asked to rate the strategies on seven speech recognition and sound quality scales. After 6 months' experience with SPEAK, patients showed significantly improved mean performance on a range of speech recognition measures in quiet and noise. When mean subjective ratings were compared over time there were no significant differences noted between strategies. However, many individuals rated the SPEAK strategy better for two or more of the seven subjective measures. Ratings for "appreciation of music" and "quality of my own voice" in particular were generally higher for SPEAK. Improvements were realized by patients with a wide range of speech perception abilities, including those with little or no open-set speech recognition.

scholarly journals Evaluation of TIMIT Sentence List Equivalency with Adult Cochlear Implant Recipients

2012 ◽  
Vol 23 (05) ◽  
pp. 313-331 ◽  
Author(s):  
Sarah E. King ◽  
Jill B. Firszt ◽  
Ruth M. Reeder ◽  
Laura K. Holden ◽  
Michael Strube
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Confidence Intervals ◽  
Test Material ◽  
Monosyllabic Word ◽  
Retest Reliability ◽  
Open Set ◽  
Rate Of Speech ◽  
Test Retest Reliability ◽  
High Test

Background: Current measures used to determine sentence recognition abilities in cochlear implant recipients often include tests with one talker and one rate of speech. Performance with these measures may not accurately represent the speech recognition abilities of the listeners. Evaluation of cochlear implant performance should include measures that reflect realistic listening conditions. For example, the use of multiple talkers who vary in gender, rate of speech, and regional dialects represent varied communication interactions that people encounter daily. The TIMIT sentences, which use multiple talkers and incorporate these variations, provide additional test material for evaluating speech recognition. Dorman and colleagues created 34 lists of TIMIT sentences that were normalized for equal intelligibility using simulations of cochlear implant processing with normal-hearing listeners. Adults with sensorineural hearing loss who listen with cochlear implants represent a different population. Further study is needed to determine if these lists are equivalent for adult cochlear implant recipients and, if not, to identify a subset of lists that may be used with this population. Purpose: To evaluate the speech recognition equivalence of 34 TIMIT sentence lists with adult cochlear implant recipients. Research Design: A prospective study comparing test-retest results within the same group of listeners. Study Sample: Twenty-two adult cochlear implant recipients who met the inclusion criteria of at least 3 mo device use and a monosyllabic word score of 30% or greater participated in the study. Data Collection and Analysis: Participants were administered 34 TIMIT sentence lists (20 sentences per list) at each of two test sessions several months apart. List order was randomized and results scored as percent of words correct. Test-retest correlations and 95% confidence intervals for the means were used to identify equivalent lists with high test-retest reliability. Results: Mean list scores across participants ranged from 66 to 81% with an overall mean of 73%. Twenty-nine lists had high test-retest reliability. Using the overall mean as a benchmark, the 95% confidence intervals indicated that 25 of the remaining 29 lists were equivalent (e.g., the benchmark of 73% fell within the 95% confidence interval for both test and retest). Conclusions: Twenty-five of the TIMIT lists evaluated are equivalent when used with adult cochlear implant recipients who have open-set word recognition abilities. These lists may prove valuable for monitoring progress, comparing listening conditions or treatments, and developing aural rehabilitation plans for cochlear implant recipients.

scholarly journals Results for Chinese and English in a Multichannel Cochlear Implant Patient

1987 ◽  
Vol 96 (1_suppl) ◽  
pp. 126-127 ◽  
Author(s):  
S. A. Xu ◽  
R. C. Dowell ◽  
G. M. Clark
Keyword(s):  
Hearing Loss ◽  
Speech Perception ◽  
Cochlear Implant ◽  
Chinese Patient ◽  
Cochlear Prosthesis ◽  
Word Test ◽  
Open Set ◽  
Chinese And English ◽  
Speech Tracking

A multichannel cochlear prosthesis was implanted in a Chinese patient who suffered from profound sensory hearing loss. The preoperative Minimal Auditory Capabilities (MAC) battery tests in English, as well as an open set bisyllable word test, an open set sentence test, and speech tracking in Chinese indicated significant improvement of speech perception for both English and Chinese after the operation. Substantial understanding of running speech was possible in both languages without the help of lipreading.

scholarly journals Sensitivity to Pulse Phase Duration as a Marker of Neural Health Across Cochlear Implant Recipients and Electrodes

2021 ◽  
Author(s):  
Ning Zhou ◽  
Zhen Zhu ◽  
Lixue Dong ◽  
John Galvin
Keyword(s):  
Hearing Loss ◽  
Speech Recognition ◽  
Cochlear Implant ◽  
Dynamic Range ◽  
Recognition Performance ◽  
Phase Duration ◽  
Pulse Phase ◽  
Site Variation ◽  
Integration Efficiency ◽  
Charge Integration

AbstractIn cochlear implants, loudness has been shown to grow more slowly with increasing pulse phase duration (PPD) than with pulse amplitude (PA), possibly due to “leaky” charge integration. This leakiness has been recently quantified in terms of “charge integration efficiency,” defined as the log difference between the PPD dynamic range and PA dynamic range (both expressed in charge units), relative to a common threshold anchor. Such leakiness may differ across electrodes and/or test ears, and may reflect underlying neural health. In this study, we examined the across-site variation of charge integration in recipients of Cochlear© devices. PPD and PA dynamic ranges were measured relative to two threshold anchors with either a 25- or 50-microsecond PPD. Strength-duration functions, previously shown to relate to survival of spiral ganglion cells and peripheral processes, were compared to charge integration efficiency on selected electrodes. Results showed no significant or systematic relationship between the across-site variation in charge integration efficiency and electrode position or threshold levels. Charge integration efficiency was poorer with the 50-μs threshold anchor, suggesting that greater leakiness was associated with larger PPD dynamic ranges. Poorer and more variable charge integration efficiency across electrodes was associated with longer duration of any hearing loss, consistent with the idea that poor integration is related to neural degeneration. More variable integration efficiency was also associated with poorer speech recognition performance across test ears. The slopes of the strength-duration functions at maximum acceptable loudness were significantly correlated with charge integration efficiency. However, the strength-duration slopes were not predictive of duration of any hearing loss or speech recognition performance in our participants. As such, charge integration efficiency may be a better candidate to measure leakiness in neural populations across the electrode array, as well as the general health of the auditory nerve in human cochlear implant recipients.

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