scholarly journals A Multiple-Channel Cochlear Implant: An Evaluation using Nonsense Syllables

1981 ◽  
Vol 90 (3) ◽  
pp. 227-230 ◽  
Author(s):  
Graeme M. Clark ◽  
Yit Chow Tong ◽  
Lois F. Martin ◽  
Peter A. Busby ◽  
Richard C. Dowell ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Cochlear Implant ◽  
Speech Processor ◽  
Average Percentage ◽  
Multiple Channel ◽  
Wearable Unit ◽  
Nonsense Syllables

A study using nonsense syllables has shown that a multiple-channel cochlear implant with speech processor is effective in providing information about voicing and manner and to a lesser extent place distinctions. These distinctions supplement lipreading cues. Furthermore, the average percentage improvements in overall identification scores for multiple-channel electrical stimulation and lipreading compared to lipreading alone were 71 % for a laboratory-based speech processor and 122% for a wearable unit.

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.

Psychophysical and Speech Studies with an Electrotactile Speech Processor

1987 ◽  
Vol 96 (1_suppl) ◽  
pp. 87-89 ◽  
Author(s):  
P. J. Blamey
Keyword(s):  
Cochlear Implant ◽  
Pulse Rate ◽  
Pulse Width ◽  
Speech Comprehension ◽  
Electrode Position ◽  
Speech Discrimination ◽  
Formant Frequency ◽  
Speech Processor ◽  
Multiple Channel ◽  
Second Formant

A multiple-channel electrotactile speech processor worn on the fingers of one hand has been constructed. This processor implements a speech-coding strategy that presents the second formant frequency by electrode position, fundamental frequency by electrical pulse rate, and amplitude envelope by pulse width. This strategy is similar to the one used by the Nucleus cochlear implant. Psychophysical tests with normally hearing and profoundly deaf subjects have measured the discrimination of stimuli differing in pulse rate, electrode, or pulse width. The levels of performance were comparable to those for cochlear implant patients except for pulse rate discrimination. Three untrained normally hearing adults using electrotactile stimulation without hearing or lipreading scored significantly better than chance for a range of two alternative forced-choice speech discrimination tasks. Provided that subjects can learn to associate linguistically meaningful concepts with tactile sensations, an improved level of speech comprehension may be achieved when the electrotactile speech processor is used together with lipreading.

Electrically Evoked Whole Nerve Action Potentials in Ineraid Cochlear Implant Users: Responses to Different Stimulating Electrode Configurations and Comparison to Psychophysical Responses

1996 ◽  
Vol 39 (3) ◽  
pp. 453-467 ◽  
Author(s):  
Carolyn J. Brown ◽  
Paul J. Abbas ◽  
James Borland ◽  
Michael R. Bertschy
Keyword(s):  
Electrical Stimulation ◽  
Cochlear Implant ◽  
Action Potentials ◽  
Detection Threshold ◽  
Growth Function ◽  
Forward Masking ◽  
Poor Correlation ◽  
Speech Processor ◽  
Growth Functions ◽  
Nerve Action

Electrically evoked whole nerve action potentials (EAP) have been recorded from 20 Ineraid cochlear implant users in response to bipolar and/or monopolar electrical stimulation of the cochlea. EAP growth functions and refractory recovery functions were obtained for a variety of different stimulating conditions. Where possible, parallel psychophysical experiments were conducted that measured the just detectable increment in stimulus current level (JND), forward-masking functions, and detection thresholds for a range of different stimuli. Variations in EAP threshold, slope of the EAP growth function, and the rate of recovery of the EAP from the refractory state were observed both across subjects for a given place and by mode of stimulation (bipolar versus monopolar), as well as across electrodes within a subject. A poor correlation between slope of the EAP growth functions and current JNDs was obtained. However, good correlations were observed between EAP threshold and psychophysical detection threshold and between the EAP refractory recovery functions and the psychophysical forward-masking functions. Our interpretation of these findings is that these particular physiological measures are related to the excitability of the auditory nerve to electrical stimulation and further that these measures are related to performance of cochlear implant patients on listening tasks. Consequently, such information may prove to be useful in adjusting the stimulation parameters of the cochlear implant speech processor in order to maximize an individual’s performance with the device.

Using Evoked Compound Action Potentials to Assess Activation of Electrodes and Predict C-Levels in the Tempo+ Cochlear Implant Speech Processor

2010 ◽  
Vol 31 (1) ◽  
pp. 134-145 ◽  
Author(s):  
Isaac Alvarez ◽  
Angel de la Torre ◽  
Manuel Sainz ◽  
Cristina Roldán ◽  
Hansjoerg Schoesser ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Action Potentials ◽  
Speech Processor ◽  
Compound Action Potentials ◽  
Compound Action

Electrically Evoked Brainstem Responses in Cochlear Implant Recipients

1987 ◽  
Vol 96 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Richard T. Miyamoto ◽  
D. Douglas Brown
Keyword(s):  
Electrical Stimulation ◽  
Cochlear Implant ◽  
Auditory Nerve ◽  
Clinical Applications ◽  
Assessment Tools ◽  
Laboratory Setting ◽  
Recording Technique ◽  
Stimulus Artifact ◽  
Artifact Suppression ◽  
Stimulation Of

Electrical stimulation of the auditory nerve in the profoundly deaf population through implanted cochlear prostheses has increased the need for reliable electrophysiologic assessment tools. We have recorded electrically evoked brainstem responses (EABRs) in 21 subjects who have received a 3M/House cochlear implant. Recordings have been made, both intraoperatively and postoperatively, in the laboratory setting. The recording technique, methods of stimulus artifact suppression, and results of our measurements are described. Clinical applications of this technology are suggested.

scholarly journals Comparison of Electrically Evoked Compound Action Potential Thresholds and Loudness Estimates for the Stimuli Used to Program the Advanced Bionics Cochlear Implant

2010 ◽  
Vol 21 (01) ◽  
pp. 016-027 ◽  
Author(s):  
Eun Kyung Jeon ◽  
Carolyn J. Brown ◽  
Christine P. Etler ◽  
Sara O'Brien ◽  
Li-Kuei Chiou ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Dynamic Range ◽  
Compound Action Potential ◽  
Behavioral Measures ◽  
Speech Processor ◽  
Compound Action Potentials ◽  
Evoked Compound Action Potential ◽  
The Individual ◽  
The Relationship ◽  
Compound Action

Background: In the mid-1990s, Cochlear Corporation introduced a cochlear implant (CI) to the market that was equipped with hardware that made it possible to record electrically evoked compound action potentials (ECAPs) from CI users of all ages. Over the course of the next decade, many studies were published that compared ECAP thresholds with levels used to program the speech processor of the Nucleus CI. In 2001 Advanced Bionics Corporation introduced the Clarion CII cochlear implant (the Clarion CII internal device is also known as the CII Bionic Ear). This cochlear implant was also equipped with a system that allowed measurement of the ECAP. While a great deal is known about how ECAP thresholds compare with the levels used to program the speech processor of the Nucleus CI, relatively few studies have reported comparisons between ECAP thresholds and the levels used to program the speech processor of the Advanced Bionics CI. Purpose: To explore the relationship between ECAP thresholds and behavioral measures of perceptual dynamic range for the range of stimuli commonly used to program the speech processor of the Advanced Bionics CI. Research Design: This prospective and experimental study uses correlational and descriptive statistics to define the relationship between ECAP thresholds and perceptual dynamic range measures. Study Sample: Twelve postlingually deafened adults participated in this study. All were experienced users of the Advanced Bionics CI system. Data Collection and Analysis: ECAP thresholds were recorded using the commercially available SoundWave software. Perceptual measures of threshold (T-level), most comfortable level (M-level), and maximum comfortable level (C-level) were obtained using both “tone bursts” and “speech bursts.” The relationship between these perceptual and electrophysiological variables was defined using paired t-tests as well as correlation and linear regression. Results: ECAP thresholds were significantly correlated with the perceptual dynamic range measures studied; however, correlations were not strong. Analysis of the individual data revealed considerable discrepancy between the contour of ECAP threshold versus electrode function and the behavioral loudness estimates used for programming. Conclusion: ECAP thresholds recorded from Advanced Bionics cochlear implant users always indicated levels where the programming stimulus was audible for the listener. However, the correlation between ECAP thresholds and M-levels (the primary metric used to program the speech processor of the Advanced Bionics CI), while statistically significant, was quite modest. If programming levels are to be determined on the basis of ECAP thresholds, care should be taken to ensure that stimulation is not uncomfortably loud, particularly on the basal electrodes in the array.

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