Cochlear implant patients' speech understanding in background noise: effect of mismatch between electrode assigned frequencies and perceived pitch

2010 ◽  
Vol 124 (8) ◽  
pp. 828-834 ◽  
Author(s):  
W Di Nardo ◽  
A Scorpecci ◽  
S Giannantonio ◽  
F Cianfrone ◽  
C Parrilla ◽  
...  

AbstractObjective:To assess the electrode pitch function in a series of adults with postlingually implanted cochlear implants and with contralateral residual hearing, in order to investigate the correlation between the degree of frequency map mismatch and the subjects' speech understanding in quiet and noisy conditions.Design:Case series.Subjects:Seven postlingually deafened adults with cochlear implants, all with detectable contralateral residual hearing. Subjects' electrode pitch function was assessed by means of a pitch-matching test, in which they were asked to match an acoustic pitch (pure tones delivered to the non-implanted ear by an audiometer) to a perceived ‘pitch’ elicited by stimulation of the cochlear implant electrodes. A mismatch score was calculated for each subject. Speech recognition was tested using lists of sentences presented in quiet conditions and at +10, 0 and 5 dB HL signal-to-noise ratio levels (i.e. noise 10 dB HL lower than signal, noise as loud as signal and noise 5 dB HL higher than signal, respectively). Correlations were assessed using a linear regression model, with significance set at p < 0.05.Results:All patients presented some degree of mismatch between the acoustic frequencies assigned to their implant electrodes and the pitch elicited by stimulation of the same electrode, with high between-individual variability. A significant correlation (p < 0.005) was found between mismatch and speech recognition scores at +10 and 0 dB HL signal-to-noise ratio levels (r2 = 0.91 and 0.89, respectively).Conclusion:The mismatch between frequencies allocated to electrodes and the pitch perceived on stimulation of the same electrodes could partially account for our subjects' difficulties with speech understanding in noisy conditions. We suggest that these subjects could benefit from mismatch correction, through a procedure allowing individualised reallocation of frequency bands to electrodes.

2008 ◽  
Vol 18 (1) ◽  
pp. 19-24
Author(s):  
Erin C. Schafer

Children who use cochlear implants experience significant difficulty hearing speech in the presence of background noise, such as in the classroom. To address these difficulties, audiologists often recommend frequency-modulated (FM) systems for children with cochlear implants. The purpose of this article is to examine current empirical research in the area of FM systems and cochlear implants. Discussion topics will include selecting the optimal type of FM receiver, benefits of binaural FM-system input, importance of DAI receiver-gain settings, and effects of speech-processor programming on speech recognition. FM systems significantly improve the signal-to-noise ratio at the child's ear through the use of three types of FM receivers: mounted speakers, desktop speakers, or direct-audio input (DAI). This discussion will aid audiologists in making evidence-based recommendations for children using cochlear implants and FM systems.


2015 ◽  
Vol 24 (4) ◽  
pp. 477-486 ◽  
Author(s):  
Douglas P. Sladen ◽  
Todd. A. Ricketts

Purpose Several studies have been devoted to understanding the frequency information available to adult users of cochlear implants when listening in quiet. The objective of this study was to construct frequency importance functions for a group of adults with cochlear implants and a group of adults with normal hearing both in quiet and in a +10 dB signal-to-noise ratio. Method Two groups of adults, 1 with cochlear implants and 1 with normal hearing, were asked to identify nonsense syllables in quiet and in the presence of 6-talker babble while “holes” were systematically created in the speech spectrum. Frequency importance functions were constructed. Results Results showed that adults with normal hearing placed greater weight on bands 1, 3, and 4 than on bands 2, 5, and 6, whereas adults with cochlear implants placed equal weight on all bands. The frequency importance functions for each group did not differ between listening in quiet and listening in noise. Conclusions Adults with cochlear implants assign perceptual weight toward different frequency bands, though the weight assignment does not differ between quiet and noisy conditions. Generalizing these results to the broader population of adults with implants is constrained by a small sample size.


2011 ◽  
Vol 22 (09) ◽  
pp. 623-632 ◽  
Author(s):  
René H. Gifford ◽  
Amy P. Olund ◽  
Melissa DeJong

Background: Current cochlear implant recipients are achieving increasingly higher levels of speech recognition; however, the presence of background noise continues to significantly degrade speech understanding for even the best performers. Newer generation Nucleus cochlear implant sound processors can be programmed with SmartSound strategies that have been shown to improve speech understanding in noise for adult cochlear implant recipients. The applicability of these strategies for use in children, however, is not fully understood nor widely accepted. Purpose: To assess speech perception for pediatric cochlear implant recipients in the presence of a realistic restaurant simulation generated by an eight-loudspeaker (R-SPACE™) array in order to determine whether Nucleus sound processor SmartSound strategies yield improved sentence recognition in noise for children who learn language through the implant. Research Design: Single subject, repeated measures design. Study Sample: Twenty-two experimental subjects with cochlear implants (mean age 11.1 yr) and 25 control subjects with normal hearing (mean age 9.6 yr) participated in this prospective study. Intervention: Speech reception thresholds (SRT) in semidiffuse restaurant noise originating from an eight-loudspeaker array were assessed with the experimental subjects’ everyday program incorporating Adaptive Dynamic Range Optimization (ADRO) as well as with the addition of Autosensitivity control (ASC). Data Collection and Analysis: Adaptive SRTs with the Hearing In Noise Test (HINT) sentences were obtained for all 22 experimental subjects, and performance—in percent correct—was assessed in a fixed +6 dB SNR (signal-to-noise ratio) for a six-subject subset. Statistical analysis using a repeated-measures analysis of variance (ANOVA) evaluated the effects of the SmartSound setting on the SRT in noise. Results: The primary findings mirrored those reported previously with adult cochlear implant recipients in that the addition of ASC to ADRO significantly improved speech recognition in noise for pediatric cochlear implant recipients. The mean degree of improvement in the SRT with the addition of ASC to ADRO was 3.5 dB for a mean SRT of 10.9 dB SNR. Thus, despite the fact that these children have acquired auditory/oral speech and language through the use of their cochlear implant(s) equipped with ADRO, the addition of ASC significantly improved their ability to recognize speech in high levels of diffuse background noise. The mean SRT for the control subjects with normal hearing was 0.0 dB SNR. Given that the mean SRT for the experimental group was 10.9 dB SNR, despite the improvements in performance observed with the addition of ASC, cochlear implants still do not completely overcome the speech perception deficit encountered in noisy environments accompanying the diagnosis of severe-to-profound hearing loss. Conclusion: SmartSound strategies currently available in latest generation Nucleus cochlear implant sound processors are able to significantly improve speech understanding in a realistic, semidiffuse noise for pediatric cochlear implant recipients. Despite the reluctance of pediatric audiologists to utilize SmartSound settings for regular use, the results of the current study support the addition of ASC to ADRO for everyday listening environments to improve speech perception in a child's typical everyday program.


2021 ◽  
Vol 64 (3) ◽  
pp. 1073-1080
Author(s):  
Justin M. Aronoff ◽  
Leah Duitsman ◽  
Deanna K. Matusik ◽  
Senad Hussain ◽  
Elise Lippmann

Purpose Audiology clinics have a need for a nonlinguistic test for assessing speech scores for patients using hearing aids or cochlear implants. One such test, the Spectral-Temporally Modulated Ripple Test Lite for computeRless Measurement (SLRM), has been developed for use in clinics, but it, as well as the related Spectral-Temporally Modulated Ripple Test, has primarily been assessed with cochlear implant users. The main goal of this study was to examine the relationship between SLRM and the Arizona Biomedical Institute Sentence Test (AzBio) for a mixed group of hearing aid and cochlear implant users. Method Adult hearing aid users and cochlear implant users were tested with SLRM, AzBio in quiet, and AzBio in multitalker babble with a +8 dB signal-to-noise ratio. Results SLRM scores correlated with both AzBio recognition scores in quiet and in noise. Conclusions The results indicated that there is a significant relationship between SLRM and AzBio scores when testing a mixed group of cochlear implant and hearing aid users. This suggests that SLRM may be a useful nonlinguistic test for use with individuals with a variety of hearing devices.


2015 ◽  
Vol 24 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Douglas P. Sladen ◽  
Amanda Zappler

Purpose To determine whether older cochlear implant (CI) listeners differ from younger CI listeners on measures of speech understanding, music perception, and health-related quality of life (HRQoL). In the study, the authors hypothesized that speech recognition would be more difficult for older adults, especially in noisy conditions. Performance on music perception was expected to be lower for older implanted listeners. No differences between age groups were expected on HRQoL. Method Twenty older (>60 years) and 20 younger (<60 years) implanted adults participated. Speech understanding was assessed using words and sentences presented in quiet, and sentences presented at +15, +10, and +5 dB signal-to-noise ratio conditions. Music perception was tested using the University of Washington Clinical Assessment of Music, and HRQoL was measured using the Njimegen CI survey. Results Speech understanding was significantly lower for the older compared with the younger group in all conditions. Older implanted adults showed lower performance on music perception compared with younger implanted adults on 1 of 3 subtests. Older adults reported lower HRQoL benefit than younger adults on 3 of 6 subdomains. Conclusion Data indicate that older CI listeners performed more poorly than younger CI listeners, although group differences appear to be task specific.


Author(s):  
Jourdan T. Holder ◽  
Adrian L. Taylor ◽  
Linsey W. Sunderhaus ◽  
Rene H. Gifford

Background: Despite improvements in cochlear implant (CI) technology, pediatric CI recipients continueto have more difficulty understanding speech than their typically hearing peers in background noise. Avariety of strategies have been evaluated to help mitigate this disparity, such as signal processing, remotemicrophone technology, and microphone placement. Previous studies regarding microphoneplacement used speech processors that are now dated, and most studies investigating the improvementof speech recognition in background noise included adult listeners only.Purpose: The purpose of the present study was to investigate the effects of microphone location andbeamforming technology on speech understanding for pediatric CI recipients in noise.Research Design: A prospective, repeated-measures, within-participant design was used to compareperformance across listening conditions.Study Sample: A total of nine children (aged 6.6 to 15.3 years) with at least one Advanced Bionics CIwere recruited for this study.Data Collection and Analysis: The Basic English Lexicon Sentences and AzBio Sentences were presentedat 0° azimuth at 65-dB SPL in +5 signal-to-noise ratio noise presented from seven speakers usingthe R-SPACE system (Advanced Bionics, Valencia, CA). Performance was compared across three omnidirectionalmicrophone configurations (processor microphone, T-Mic 2, and processor + T-Mic 2) andtwo directional microphone configurations (UltraZoom and auto UltraZoom). The two youngest participantswere not tested in the directional microphone configurations.Results: No significant differences were found between the various omnidirectional microphone configurations.UltraZoom provided significant benefit over all omnidirectional microphone configurations(T-Mic 2, p = 0.004, processor microphone, p < 0.001, and processor microphone + T-Mic 2, p = 0.018)but was not significantly different from auto UltraZoom (p = 0.176).Conclusions: All omnidirectional microphone configurations yielded similar performance, suggesting thata child’s listening performance in noise will not be compromised by choosing the microphone configurationbest suited for the child. UltraZoom (adaptive beamformer) yielded higher performance than all omnidirectional microphonesin moderate background noise for adolescents aged 9 to 15 years. The implicationsof these data suggest that for older children who are able to reliably use manual controls, UltraZoom willyield significantly higher performance in background noise when the target is in front of the listener.


2020 ◽  
Vol 63 (11) ◽  
pp. 3855-3864
Author(s):  
Wanting Huang ◽  
Lena L. N. Wong ◽  
Fei Chen ◽  
Haihong Liu ◽  
Wei Liang

Purpose Fundamental frequency (F0) is the primary acoustic cue for lexical tone perception in tonal languages but is processed in a limited way in cochlear implant (CI) systems. The aim of this study was to evaluate the importance of F0 contours in sentence recognition in Mandarin-speaking children with CIs and find out whether it is similar to/different from that in age-matched normal-hearing (NH) peers. Method Age-appropriate sentences, with F0 contours manipulated to be either natural or flattened, were randomly presented to preschool children with CIs and their age-matched peers with NH under three test conditions: in quiet, in white noise, and with competing sentences at 0 dB signal-to-noise ratio. Results The neutralization of F0 contours resulted in a significant reduction in sentence recognition. While this was seen only in noise conditions among NH children, it was observed throughout all test conditions among children with CIs. Moreover, the F0 contour-induced accuracy reduction ratios (i.e., the reduction in sentence recognition resulting from the neutralization of F0 contours compared to the normal F0 condition) were significantly greater in children with CIs than in NH children in all test conditions. Conclusions F0 contours play a major role in sentence recognition in both quiet and noise among pediatric implantees, and the contribution of the F0 contour is even more salient than that in age-matched NH children. These results also suggest that there may be differences between children with CIs and NH children in how F0 contours are processed.


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