Optimizing Frequency-to-Electrode Allocation in Cochlear Implants

2004 ◽  
Vol 15 (08) ◽  
pp. 574-584 ◽  
Author(s):  
Jaime R. Leigh ◽  
Katherine R. Henshall ◽  
Colette M. McKay
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Information Transmission ◽  
Cochlear Implants ◽  
Low Frequency ◽  
Low Frequencies ◽  
Variable Effect ◽  
Filter Bandwidth

This study tested the hypothesis that speech perception of cochlear implant users could be improved by increasing the number of electrodes allocated to frequencies below 2.6 kHz, with correspondingly fewer electrodes allocated above this point. Eight users of the Nucleus CI22 implant participated and wore experimental maps in which the widths of the analysis filters were altered to provide either two or three extra low-frequency channels. Speech perception was tested following periods of take-home experience. Information transmission analysis of vowel and consonant confusions appear to support our hypothesis, showing that vowel first formant information was significantly better perceived with the experimental map and that consonant information was not significantly different. The results of CNC word testing appear to contradict this result, showing that the experimental map degraded both vowel and consonant perception. Overall, the experimental map had a small and variable effect on speech perception. These results do not support our hypothesis and indicate that further research is needed to investigate the possible effects of narrowing the filter bandwidth in low frequencies, as done in this experiment.

Criteria for Selecting an Optimal Device for the Contralateral Ear of Children with a Unilateral Cochlear Implant

2015 ◽  
Vol 20 (5) ◽  
pp. 314-321 ◽  
Author(s):  
Sung-Wook Jeong ◽  
Min-Young Kang ◽  
Lee-Suk Kim
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Hearing Threshold ◽  
Low Frequency ◽  
Hearing Level ◽  
Monosyllabic Word ◽  
Low Frequencies ◽  
Speech Perception In Noise ◽  
Clinical Criteria ◽  
Contralateral Ear

Objective: To identify clinical criteria for selecting the aiding device for the contralateral ear of children with a unilateral cochlear implant (CI). Methods: Sixty-five children, including 36 bilateral CI users and 29 bimodal users, participated in the study. A speech perception test (monosyllabic word test) in noise was administered. The target speech (65 dB sound pressure level) was presented from the front loudspeaker, and noise (10 dB signal-to-noise ratio) was presented from 3 directions: from in front of the child and 90° to the child's right and left sides. The test was performed using the first CI alone and under bilateral CI or bimodal conditions. The bilateral benefits to speech perception in noise were compared between bilateral CI users and bimodal users. Results: Significant benefits in speech perception in noise were evident in bilateral CI users in all 3 noise conditions. In bimodal users, the hearing threshold at low frequencies of ≤1 kHz in the nonimplanted ear affected the bilateral benefit. Bimodal users with a low-frequency hearing threshold ≤90 dB hearing level (HL) showed a significant bilateral benefit in various noise conditions. By contrast, bimodal users with a low-frequency hearing threshold >90 dB HL showed no significant bilateral benefits in all 3 noise conditions. Conclusions: Bilateral CI and bimodal listening provide better speech perception in noise than unilateral CI alone in children. The contralateral CI is better than bimodal listening for children with a low-frequency hearing threshold >90 dB HL. A hearing threshold at low frequencies of ≤1 kHz may be a good criterion for deciding on the type of device for the contralateral ear of children with a unilateral CI.

The Effects of Frequency Response on Speech Perception for Cochlear Implant Users

2003 ◽  
Vol 14 (10) ◽  
pp. 582-591 ◽  
Author(s):  
Alexandra Weatherby ◽  
Katherine R. Henshall ◽  
Colette M. McKay
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Cochlear Implants ◽  
High Frequency ◽  
Signal To Noise Ratio ◽  
Low Frequency ◽  
Frequency Range ◽  
Speech Processor ◽  
Minimal Difference ◽  
Better Than

The aim of this study was to investigate the effects on speech perception of manipulating filter gains in a cochlear implant speech processor. Five implantees, who use the CI22 implant and Spectra processor manufactured by Cochlear Ltd, participated. Four experimental maps were created that were identical to their clinical map except for the profile of gains across the filters. Experimental gain profiles had rising or falling gains across the frequency range, or emphasized or de-emphasized the middle frequencies, relative to the clinical map. Perception of CNC (consonant-vowel-consonant) words at 70 dB SPL was significantly better with the clinical map than with all experimental maps, whereas at the lower level (60 dB SPL) there was minimal difference between the maps, with the low-frequency emphasis map giving significantly better scores than the high-frequency emphasis map. Perception of sentences at 70 dB SPL with a signal-to-noise ratio of +10 dB was better with the high-frequency emphasis map than with the low-frequency emphasis map. None of these best-conditions, however, were statistically better than the clinical map. The results highlighted the importance of signal audibility for speech perception with cochlear implants.

scholarly journals Auditory Speech Perception Development in Relation to Patient's Age with Cochlear Implant

2016 ◽  
Vol 21 (03) ◽  
pp. 206-212 ◽  
Author(s):  
Grace Ciscare ◽  
Erika Mantello ◽  
Carla Fortunato-Queiroz ◽  
Miguel Hyppolito ◽  
Ana Reis
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Cochlear Implants ◽  
Statistical Difference ◽  
Hearing Aid ◽  
Age Groups ◽  
Auditory Thresholds ◽  
Caregiver Education ◽  
Auditory Speech ◽  
Hearing Aid Use

Introduction A cochlear implant in adolescent patients with pre-lingual deafness is still a debatable issue. Objective The objective of this study is to analyze and compare the development of auditory speech perception in children with pre-lingual auditory impairment submitted to cochlear implant, in different age groups in the first year after implantation. Method This is a retrospective study, documentary research, in which we analyzed 78 reports of children with severe bilateral sensorineural hearing loss, unilateral cochlear implant users of both sexes. They were divided into three groups: G1, 22 infants aged less than 42 months; G2, 28 infants aged between 43 to 83 months; and G3, 28 older than 84 months. We collected medical record data to characterize the patients, auditory thresholds with cochlear implants, assessment of speech perception, and auditory skills. Results There was no statistical difference in the association of the results among groups G1, G2, and G3 with sex, caregiver education level, city of residence, and speech perception level. There was a moderate correlation between age and hearing aid use time, age and cochlear implants use time. There was a strong correlation between age and the age cochlear implants was performed, hearing aid use time and age CI was performed. Conclusion There was no statistical difference in the speech perception in relation to the patient's age when cochlear implant was performed. There were statistically significant differences for the variables of auditory deprivation time between G3 - G1 and G2 - G1 and hearing aid use time between G3 - G2 and G3 - G1.

scholarly journals Mismatch Negativity in Children with Cochlear Implant

2019 ◽  
Vol 23 (03) ◽  
pp. e292-e298
Author(s):  
Natalia Martinez Fernandes ◽  
Daniela Gil ◽  
Marisa Frasson de Azevedo
Keyword(s):  
Speech Perception ◽  
Language Development ◽  
Cochlear Implant ◽  
Cochlear Implants ◽  
Family Involvement ◽  
Mismatch Negativity ◽  
Control Group ◽  
Study Group ◽  
Cross Sectional ◽  
Hearing Children

Introduction The mismatch negativity (MMN) is a negative long-latency auditory potential elicited by any discriminable change in a repetitive aspect of auditory stimulation. This evoked potential can provide cortical information about the sound processing, including in children who use cochlear implants. Objective To identify MMN characteristics regarding latency, amplitude, and wave area in cochlear implanted children and to identify associations among language development, speech perception and family involvement. Methods This is a descriptive, observational, cross-sectional study, which compared two groups: study group—children with cochlear implant, and control group—hearing children. The children were submitted to MMN evaluation with non-verbal tone burst stimulus, differing in frequency in sound field at 70 dBHL, with SmartEP equipment (Intelligent Hearing Systems, Miami, FL, USA). Speech perception and language development questionnaires were also applied, and the family participation in the rehabilitation process was classified. Results The occurrence of MMN was 73.3% for the control group and 53.3% for the study group. Values of latency, amplitude and area of MMN of children using cochlear implants were similar to those of hearing children, and did not differ between groups. The occurrence of MMN was not correlated to the variables of hearing, language and family categories. Conclusion Children with cochlear implants showed similar MMN responses to those of the children in the control group, with mean latency, amplitude and area of 208.9 ms (±12.8), -2.37 μV (±0.38) and 86.5 μVms (±23.4), respectively. There was no correlation between the presence of MMN and children's performance in the auditory and language development tests or family involvement during rehabilitation.

Speech Perception with a Single-Channel Cochlear Implant

1990 ◽  
Vol 33 (2) ◽  
pp. 229-237 ◽  
Author(s):  
Arlene Earley Carney ◽  
Marjorie Kienle ◽  
Richard T. Miyamoto
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Cochlear Implants ◽  
Single Channel ◽  
Performance Level ◽  
The Subject ◽  
Overall Performance

Suprasegmental and segmental speech perception tasks were administered to 8 patients with single-channel cochlear implants. Suprasegmental tasks included the recognition of syllable number, syllabic stress, and intonation. Segmental tasks included the recognition of vowels and consonants in three modalities: visual only, implant only, and visual + implant. Results were compared to those obtained from artificially deafened adults using a single-channel vibrotactile device (Carney, 1988; Carney & Beachler, 1986). The patterns of responses for both suprasegmental and segmental tasks were highly similar for both groups of subjects, despite differences between the characteristics of the subject samples. These results suggest that single-channel sensory devices, whether they be cochlear implants or vibrotactile aids, produce similar patterns of speech perception errors, even when differences are observed in overall performance level.

scholarly journals An Attempt to Improve Bilateral Cochlear Implants by Increasing the Distance between Electrodes and Providing Complementary Information to the Two Ears

2010 ◽  
Vol 21 (01) ◽  
pp. 052-065 ◽  
Author(s):  
Richard S. Tyler ◽  
Shelley A. Witt ◽  
Camille C. Dunn ◽  
Ann Perreau ◽  
Aaron J. Parkinson ◽  
...  
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Cochlear Implants ◽  
Speech Processing ◽  
Processing Strategy ◽  
Bilateral Cochlear Implants ◽  
Channel Interaction ◽  
Consonant Recognition ◽  
Bilateral Cochlear Implant ◽  
Input Spectrum

Objectives: The purpose of this investigation was to determine if adult bilateral cochlear implant recipients could benefit from using a speech processing strategy in which the input spectrum was interleaved among electrodes across the two implants. Design: Two separate experiments were conducted. In both experiments, subjects were tested using a control speech processing strategy and a strategy in which the full input spectrum was filtered so that only the output of half of the filters was audible to one implant, while the output of the alternative filters was audible to the other implant. The filters were interleaved in a way that created alternate frequency “holes” between the two cochlear implants. Results: In experiment one, four subjects were tested on consonant recognition. Results indicated that one of the four subjects performed better with the interleaved strategy, one subject received a binaural advantage with the interleaved strategy that they did not receive with the control strategy, and two subjects showed no decrement in performance when using the interleaved strategy. In the second experiment, 11 subjects were tested on word recognition, sentences in noise, and localization (it should be noted that not all subjects participated in all tests). Results showed that for speech perception testing one subject achieved significantly better scores with the interleaved strategy on all tests, and seven subjects showed a significant improvement with the interleaved strategy on at least one test. Only one subject showed a decrement in performance on all speech perception tests with the interleaved strategy. Out of nine subjects, one subject preferred the sound quality of the interleaved strategy. No one performed better on localization with the interleaved strategy. Conclusion: Data from this study indicate that some adult bilateral cochlear implant recipients can benefit from using a speech processing strategy in which the input spectrum is interleaved among electrodes across the two implants. It is possible that the subjects in this study who showed a significant improvement with the interleaved strategy did so because of less channel interaction; however, this hypothesis was not directly tested.

scholarly journals Effect of cochlear implant electrode insertion on middle-ear function as measured by intra-operative laser Doppler vibrometry

2009 ◽  
Vol 123 (7) ◽  
pp. 723-729 ◽  
Author(s):  
N Donnelly ◽  
A Bibas ◽  
D Jiang ◽  
D-E Bamiou ◽  
C Santulli ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Middle Ear ◽  
Low Frequency ◽  
Laser Doppler ◽  
Frequency Function ◽  
Laser Doppler Vibrometry ◽  
Variable Effect ◽  
Custom Made ◽  
Electrode Insertion ◽  
The Impact

AbstractHypothesis:The aim of this study was to investigate the impact of cochlear implant electrode insertion on middle-ear low frequency function in humans.Background:Preservation of residual low frequency hearing with addition of electrical speech processing can improve the speech perception abilities and hearing in noise of cochlear implant users. Preservation of low frequency hearing requires an intact middle-ear conductive mechanism in addition to intact inner-ear mechanisms. Little is known about the effect of a cochlear implant electrode on middle-ear function.Methods:Stapes displacement was measured in seven patients undergoing cochlear implantation. Measurements were carried out intra-operatively before and after electrode insertion. Each patient acted as his or her own control. Sound was delivered into the external auditory canal via a speaker and calibrated via a probe microphone. The speaker and probe microphone were integrated into an individually custom-made ear mould. Ossicular displacement in response to a multisine stimulus at 80 dB SPL was measured at the incudostapedial joint via the posterior tympanotomy, using an operating microscope mounted laser Doppler vibrometry system.Results:Insertion of a cochlear implant electrode into the scala tympani had a variable effect on stapes displacement. In three patients, there was little change in stapes displacement following electrode insertion. In two patients, there was a significant increase, while in a further two there was a significant reduction in stapes displacement. This variability may reflect alteration of cochlear impedance, possibly due to differing loss of perilymph associated with the electrode insertion.Conclusion:Insertion of a cochlear implant electrode produces a change in stapes displacement at low frequencies, which may have an effect on residual low frequency hearing thresholds.

Comparison of Sensory Aids in Deaf Children

1989 ◽  
Vol 98 (8_suppl) ◽  
pp. 2-7 ◽  
Author(s):  
Richard T. Miyamoto ◽  
Mary Joe Osberger ◽  
Wendy A. Myres ◽  
Amy J. Robbins ◽  
Kathy Kessler ◽  
...  
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Cochlear Implants ◽  
Channel Coding ◽  
Single Channel ◽  
Deaf Children ◽  
Implant Design ◽  
Detection Level ◽  
Coding Scheme ◽  
Auditory Speech

A speech perception hierarchy has been developed and applied to assess the influence of cochlear implants and tactile aids on the acquisition of auditory, speech, and language skills in deaf children. Encouraging improvements were noted with both types of sensory aids at the detection level. The House 3M and Nucleus cochlear implant designs appear to offer advantages over the Tactaid II in providing ancillary speech perception cues to deaf children. Preliminary observations suggest that the multichannel cochlear implant design may be superior to the single-channel coding scheme.

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