scholarly journals Rate discrimination, gap detection and ranking of temporal pitch in cochlear implant users

2016 ◽  
Vol 17 (4) ◽  
pp. 371-382 ◽  
Author(s):  
Stefano Cosentino ◽  
Robert P. Carlyon ◽  
John M. Deeks ◽  
Wendy Parkinson ◽  
Julie A. Bierer
Keyword(s):  
Cochlear Implant ◽  
Gap Detection ◽  
Rate Discrimination

scholarly journals Effect of stimulus polarity on detection thresholds in cochlear implant users: relationships with average threshold, gap detection, and rate discrimination

2018 ◽  
Author(s):  
Robert P. Carlyon ◽  
Stefano Cosentino ◽  
John M. Deeks ◽  
Wendy Parkinson ◽  
Julie A. Arenberg
Keyword(s):  
Cochlear Implant ◽  
High Amplitude ◽  
Gap Detection ◽  
Detection Thresholds ◽  
Polarity Effect ◽  
Modelling Studies ◽  
Neural Survival ◽  
Rate Discrimination ◽  
Central High ◽  
Anodic Stimulation

AbstractPrevious psychophysical and modelling studies suggest that cathodic stimulation by a cochlear implant (CI) may preferentially activate the peripheral processes of the auditory nerve, whereas anodic stimulation may preferentially activate the central axons. Because neural degeneration typically starts with loss of the peripheral processes, lower thresholds for cathodic than for anodic stimulation may indicate good local neural survival. We measured thresholds for 99-pulse-per-second trains of triphasic (TP) pulses where the central high-amplitude phase was either anodic (TP-A) or cathodic (TP-C). Thresholds were obtained in monopolar mode from four or five electrodes and a total of eight ears from subjects implanted with the Advanced Bionics CI. When between–subject differences were removed, there was a modest but significant correlation between the polarity effect (TP-C threshold minus TP-A threshold) and the average of TP-C and TP-A thresholds, consistent with the hypothesis that a large polarity effect corresponds to good neural survival. When data were averaged across electrodes for each subject, relatively low thresholds for TP-C correlated with a high “upper limit” (the pulse rate up to which pitch continues to increase) from a previous study [Cosentino S, Carlyon RP, Deeks JM, Parkinson W, Bierer JA (2016) Rate discrimination, gap detection and ranking of temporal pitch in cochlear implant users. J Assoc Otolaryngol 17:371– 382]. Overall the results provide modest indirect support for the hypothesis that the polarity effect provides an estimate of local neural survival.

Performance of Some of the Better Cochlear-Implant Patients

1989 ◽  
Vol 32 (4) ◽  
pp. 887-911 ◽  
Author(s):  
Richard S. Tyler ◽  
Brian C. J. Moore ◽  
Francis K. Kuk
Keyword(s):  
Word Recognition ◽  
Cochlear Implant ◽  
Scaling Analysis ◽  
Gap Detection ◽  
Environmental Sound ◽  
Sound Perception ◽  
Detection Thresholds ◽  
Closed Set ◽  
Open Set ◽  
Wide Range

The main purpose of this study was to provide an independent corroboration of open-set word recognition in some of the better cochlear-implant patients. These included the Chorimac, Nucleus (one group from the U.S.A. and one group from Hannover, Germany), Symbion, Duren/Cologne and 3M/Vienna implants. Three experiments are reported: (1) word recognition in word lists and in sentences; (2) environmental sound perception, and (3) gap detection. On word recognition, the scores of 6 Chorimac patients averaged 2.5% words and 0.7% words in sentences correct in the French tests. In the German tests, the scores averaged 17% words and 10% words in sentences for 10 Duren/Cologne patients, 15% words and 16% words in sentences for 9 3M/Vienna patients, and 10% words and 16% words in sentences (3% to 26%) for 10 Nucleus/Hannover patients. In the English tests, the scores averaged 11% words and 29.6% words in sentences for l0 Nucleus-U.S.A. patients, and 13.7% words and 35.7% words in sentences for the 9 Symbion patients. The ability to recognize recorded environmental sounds was measured with a closed set of 18 sounds. Performance averaged 23% correct for Chorimac patients, 41% correct for 3M/Vienna patients, 44% correct for Nucleus/Hannover patients, 21% correct for Duren/Cologne patients, 58% correct for Nucleus/U.S.A. patients, and 83% correct for Symbion patients. A multidimensional scaling analysis suggested that patients were, in part, utilizing information about the envelope and about the periodic/aperiodic nature of some of the sounds. Gap detection thresholds with a one-octave wide noise centered at 500 Hz varied widely among patients. Typically, patients with gap thresholds less than 40 ms showed a wide range of performance on speech perception tasks, whereas patients with gap-detection thresholds greater than 40 ms showed poor word recognition skills.

scholarly journals Effect of chronic stimulation and stimulus level on temporal processing by cochlear implant listeners

2018 ◽  
Author(s):  
Robert P. Carlyon ◽  
François Guérit ◽  
Alexander J. Billig ◽  
Yu Chuen Tam ◽  
Frances Harris ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Temporal Processing ◽  
Dynamic Range ◽  
Stimulus Level ◽  
Adaptive Procedure ◽  
Direct Stimulation ◽  
Upper Limit ◽  
Upper Limits ◽  
Series Of Experiments ◽  
Rate Discrimination

AbstractA series of experiments investigated potential changes in temporal processing during the months following activation of a cochlear implant (CI) and as a function of stimulus level. Experiment 1 tested patients on the day of implant activation and two and six months later. All stimuli were presented using direct stimulation of a single apical electrode. The dependent variables were rate discrimination ratios (RDRs) for pulse trains with rates centred on 120 pulses per second (pps), obtained using an adaptive procedure, and a measure of the upper limit of temporal pitch, obtained using a pitch-ranking procedure.All stimuli were presented at their most comfortable level (MCL). RDRs decreased from 1.23 to 1.16 and the upper limit increased from 357 to 485 pps from 0 to 2 months post-activation, with no overall change from 2 to 6 months. Because MCLs and hence the testing level increased across sessions, two further experiments investigated whether the performance changes observed across sessions could be due to level differences. Experiment 2 re-tested a subset of subjects at 9 months post-activation, using current levels similar to those used at 0 months. Although the stimuli sounded softer, some subjects showed lower RDRs and/or higher upper limits at this re-test. Experiment 3 measured RDRs and the upper limit for a separate group of subjects at levels equal to 60%, 80%, and 100% of the dynamic range. RDRs decreased with increasing level. The upper limit increased with increasing level for most subjects, with two notable exceptions. Implications of the results for temporal plasticity are discussed, along with possible influences of the effects of level and of across-session learning.

Psychoacoustic and Demographic Factors for Speech Recognition of Older Adult Cochlear Implant Users

2020 ◽  
Vol 63 (6) ◽  
pp. 1712-1725
Author(s):  
Xin Luo ◽  
Courtney Kolberg ◽  
Kathryn R. Pulling ◽  
Tamiko Azuma
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Discrimination Performance ◽  
Demographic Factors ◽  
Small Sample ◽  
Gap Detection ◽  
Sentence Recognition ◽  
Speech Reception Thresholds ◽  
Effects Of Aging ◽  
Better Than

Purpose This study aimed to evaluate the effects of aging and cochlear implant (CI) on psychoacoustic and speech recognition abilities and to assess the relative contributions of psychoacoustic and demographic factors to speech recognition of older CI (OCI) users. Method Twelve OCI users, 12 older acoustic-hearing (OAH) listeners age-matched to OCI users, and 12 younger normal-hearing (YNH) listeners underwent tests of temporal amplitude modulation detection, temporal gap detection in noise, and spectral–temporal modulated ripple discrimination. Speech reception thresholds were measured for sentence recognition in multitalker, speech-babble noise. Results Statistical analyses showed that, for the small sample of OAH listeners, the degree of hearing loss did not significantly affect any outcome measure. Temporal resolution, spectral resolution, and speech recognition all significantly degraded with both age and the use of a CI (i.e., YNH better than OAH and OAH better than OCI performance). Although both were significantly correlated with OCI users' speech recognition, the duration of CI use no longer had a significant effect on speech recognition once the effect of spectral–temporal ripple discrimination performance was taken into account. For OAH listeners, the only significant predictor of speech recognition was temporal gap detection performance. Conclusion The preliminary results suggest that speech recognition of OCI users may improve with longer duration of CI use, mainly due to higher perceptual acuity to spectral–temporal modulated ripples in acoustic stimuli.

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