Frequency Importance Functions in Quiet and Noise for Adults With Cochlear Implants

2015 ◽  
Vol 24 (4) ◽  
pp. 477-486 ◽  
Author(s):  
Douglas P. Sladen ◽  
Todd. A. Ricketts
Keyword(s):  
Cochlear Implants ◽  
Signal To Noise Ratio ◽  
Small Sample Size ◽  
Normal Hearing ◽  
Small Sample ◽  
Equal Weight ◽  
Signal To Noise ◽  
Speech Spectrum ◽  
Noisy Conditions ◽  
Listening In Noise

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.

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 ◽  
...  
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Cochlear Implants ◽  
Signal To Noise Ratio ◽  
Residual Hearing ◽  
Speech Understanding ◽  
Signal To Noise ◽  
Electrode Pitch ◽  
Noisy Conditions ◽  
Stimulation Of

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.

Effects of Fundamental Frequency Contours on Sentence Recognition in Mandarin-Speaking Children With Cochlear Implants

2020 ◽  
Vol 63 (11) ◽  
pp. 3855-3864
Author(s):  
Wanting Huang ◽  
Lena L. N. Wong ◽  
Fei Chen ◽  
Haihong Liu ◽  
Wei Liang
Keyword(s):  
Cochlear Implants ◽  
Fundamental Frequency ◽  
Signal To Noise Ratio ◽  
Lexical Tone ◽  
Signal To Noise ◽  
Sentence Recognition ◽  
Test Conditions ◽  
Age Appropriate ◽  
F0 Contour ◽  
Appropriate Sentences

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.

Selecting the Optimal FM System for Children With Cochlear Implants

2008 ◽  
Vol 18 (1) ◽  
pp. 19-24
Author(s):  
Erin C. Schafer
Keyword(s):  
Speech Recognition ◽  
Cochlear Implants ◽  
Empirical Research ◽  
Background Noise ◽  
Signal To Noise Ratio ◽  
Evidence Based ◽  
Signal To Noise ◽  
Speech Processor ◽  
System Input ◽  
Optimal Type

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.

Cytomegalovirus and the Brain

PEDIATRICS ◽  
1987 ◽  
Vol 79 (5) ◽  
pp. 841-841
Author(s):  
THOMAS J. CONBOY ◽  
ROBERT F. PASS ◽  
THOMAS J. BOLL
Keyword(s):  
Hearing Loss ◽  
Sample Size ◽  
Small Sample Size ◽  
Normal Hearing ◽  
Small Sample ◽  
Intellectual Impairment ◽  
Intellectual Performance ◽  
Asymptomatic Children ◽  
The Brain

In Reply.— We agree with Ades et al that our study1 was not definitive in ruling out the possibility of intellectual impairment in children born with asymptomatic cytomegalovirus and said as much in our discussion, mentioning the relatively small sample size as one of several caveats. It is important to note that our study included only asymptomatic children with normal hearing in order not to confound the effects of hearing loss on intellectual performance with possible effects of the virus.

Development of a quick speech-in-noise test for measuring signal-to-noise ratio loss in normal-hearing and hearing-impaired listeners

2004 ◽  
Vol 116 (4) ◽  
pp. 2395-2405 ◽  
Author(s):  
Mead C. Killion ◽  
Patricia A. Niquette ◽  
Gail I. Gudmundsen ◽  
Lawrence J. Revit ◽  
Shilpi Banerjee
Keyword(s):  
Signal To Noise Ratio ◽  
Normal Hearing ◽  
Hearing Impaired ◽  
Signal To Noise ◽  
Speech In Noise ◽  
Noise Test ◽  
Noise Ratio ◽  
Measuring Signal

Detection of Hearing Loss Using 2f2-f1 and 2f1-f2 Distortion-Product Otoacoustic Emissions

2005 ◽  
Vol 48 (5) ◽  
pp. 1165-1186 ◽  
Author(s):  
Tracy S. Fitzgerald ◽  
Beth A. Prieve
Keyword(s):  
Otoacoustic Emissions ◽  
Signal To Noise Ratio ◽  
Normal Hearing ◽  
Hearing Impaired ◽  
Distortion Product Otoacoustic Emissions ◽  
Signal To Noise ◽  
Primary Level ◽  
Distortion Product ◽  
Hearing Status ◽  
Stimulus Parameters

Although many distortion-product otoacoustic emissions (DPOAEs) may be measured in the ear canal in response to 2 pure tone stimuli, the majority of clinical studies have focused exclusively on the DPOAE at the frequency 2f1-f2. This study investigated another DPOAE, 2f2-f1, in an attempt to determine the following: (a) the optimal stimulus parameters for its clinical measurement and (b) its utility in differentiating between normal-hearing and hearing-impaired ears at low-to-mid frequencies (≤2000 Hz) when measured either alone or in conjunction with the 2f1-f2 DPOAE. Two experiments were conducted. In Experiment 1, the effects of primary level, level separation, and frequency separation (f2/f1) on 2f2-f1 DPOAE level were evaluated in normal-hearing ears for low-to-mid f2 frequencies (700–2000 Hz). Moderately high-level primaries (60–70 dB SPL) presented at equal levels or with f2 slightly higher than f1 produced the highest 2f2-f1 DPOAE levels. When the f2/f1 ratio that produced the highest 2f2-f1 DPOAE levels was examined across participants, the mean optimal f2/f1 ratio across f2 frequencies and primary level separations was 1.08. In Experiment 2, the accuracy with which DPOAE level or signal-to-noise ratio identified hearing status at the f2 frequency as normal or impaired was evaluated using clinical decision analysis. The 2f2-f1 and 2f1-f2 DPOAEs were measured from both normal-hearing and hearing-impaired ears using 2 sets of stimulus parameters: (a) the traditional parameters for measuring the 2f1-f2 DPOAE (f2/f1 = 1.22; L1, L2 = 65, 55 dB SPL) and (b) the new parameters that were deemed optimal for the 2f2-f1 DPOAE in Experiment 1 (f2/f1 = 1.073, L1 and L2 = 65 dB SPL). Identification of hearing status using 2f2-f1 DPOAE level and signal-to-noise ratio was more accurate when the new stimulus parameters were used compared with the results achieved when the 2f2-f1 DPOAE was recorded using the traditional parameters. However, identification of hearing status was less accurate for the 2f2-f1 DPOAE measured using the new parameters than for the 2f1-f2 DPOAE measured using the traditional parameters. No statistically significant improvements in test performance were achieved when the information from the 2 DPOAEs was combined, either by summing the DPOAE levels or by using logistic regression analysis.

Detection and Recognition of Stop Consonants by Normal.Hearing and Hearing Impaired Listeners

1992 ◽  
Vol 35 (4) ◽  
pp. 942-949 ◽  
Author(s):  
Christopher W. Turner ◽  
David A. Fabry ◽  
Stephanie Barrett ◽  
Amy R. Horwitz
Keyword(s):  
Signal To Noise Ratio ◽  
Recognition Performance ◽  
Normal Hearing ◽  
Hearing Impaired ◽  
Stop Consonants ◽  
Signal To Noise ◽  
Short Term ◽  
Masking Noise ◽  
Noise Ratio ◽  
Detection And Recognition

This study examined the possibility that hearing-impaired listeners, in addition to displaying poorer-than-normal recognition of speech presented in background noise, require a larger signal-to-noise ratio for the detection of the speech sounds. Psychometric functions for the detection and recognition of stop consonants were obtained from both normal-hearing and hearing-impaired listeners. Expressing the speech levels in terms of their short-term spectra, the detection of consonants for both subject groups occurred at the same signal-to-noise ratio. In contrast, the hearing-impaired listeners displayed poorer recognition performance than the normal-hearing listeners. These results imply that the higher signal-to-noise ratios required for a given level of recognition by some subjects with hearing loss are not due in part to a deficit in detection of the signals in the masking noise, but rather are due exclusively to a deficit in recognition.

scholarly journals Discrimination of Stochastic Frequency Modulation by Cochlear Implant Users

2015 ◽  
Vol 26 (06) ◽  
pp. 572-581 ◽  
Author(s):  
Stanley Sheft ◽  
Min-Yu Cheng ◽  
Valeriy Shafiro
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Stimulus Duration ◽  
Frequency Modulation ◽  
Speech Intelligibility ◽  
Signal To Noise Ratio ◽  
Normal Hearing ◽  
Signal To Noise ◽  
Common Basis ◽  
Low Rate

Background: Past work has shown that low-rate frequency modulation (FM) may help preserve signal coherence, aid segmentation at word and syllable boundaries, and benefit speech intelligibility in the presence of a masker. Purpose: This study evaluated whether difficulties in speech perception by cochlear implant (CI) users relate to a deficit in the ability to discriminate among stochastic low-rate patterns of FM. Research Design: This is a correlational study assessing the association between the ability to discriminate stochastic patterns of low-rate FM and the intelligibility of speech in noise. Study Sample: Thirteen postlingually deafened adult CI users participated in this study. Data Collection and Analysis: Using modulators derived from 5-Hz lowpass noise applied to a 1-kHz carrier, thresholds were measured in terms of frequency excursion both in quiet and with a speech-babble masker present, stimulus duration, and signal-to-noise ratio in the presence of a speech-babble masker. Speech perception ability was assessed in the presence of the same speech-babble masker. Relationships were evaluated with Pearson product–moment correlation analysis with correction for family-wise error, and commonality analysis to determine the unique and common contributions across psychoacoustic variables to the association with speech ability. Results: Significant correlations were obtained between masked speech intelligibility and three metrics of FM discrimination involving either signal-to-noise ratio or stimulus duration, with shared variance among the three measures accounting for much of the effect. Compared to past results from young normal-hearing adults and older adults with either normal hearing or a mild-to-moderate hearing loss, mean FM discrimination thresholds obtained from CI users were higher in all conditions. Conclusions: The ability to process the pattern of frequency excursions of stochastic FM may, in part, have a common basis with speech perception in noise. Discrimination of differences in the temporally distributed place coding of the stimulus could serve as this common basis for CI users.

scholarly journals Hearing in Noise: The Importance of Coding Strategies—Normal-Hearing Subjects and Cochlear Implant Users

2019 ◽  
Vol 9 (4) ◽  
pp. 734 ◽  
Author(s):  
Pierre-Antoine Cucis ◽  
Christian Berger-Vachon ◽  
Ruben Hermann ◽  
Fabien Millioz ◽  
Eric Truy ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Channel Coding ◽  
Signal To Noise Ratio ◽  
Normal Hearing ◽  
Signal To Noise ◽  
Sound Coding ◽  
Coding Schemes ◽  
Channel Strategy ◽  
Hearing In Noise ◽  
Common Signal

Two schemes are mainly used for coding sounds in cochlear implants: Fixed-Channel and Channel-Picking. This study aims to determine the speech audiometry scores in noise of people using either type of sound coding scheme. Twenty normal-hearing and 45 cochlear implant subjects participated in this experiment. Both populations were tested by using dissyllabic words mixed with cocktail-party noise. A cochlear implant simulator was used to test the normal-hearing subjects. This simulator separated the sound into 20 spectral channels and the eight most energetic were selected to simulate the Channel-Picking strategy. For normal-hearing subjects, we noticed higher scores with the Fixed-Channel strategy than with the Channel-Picking strategy in the mid-range signal-to-noise ratios (0 to +6 dB). For cochlear implant users, no differences were found between the two coding schemes but we could see a slight advantage for the Fixed-Channel strategies over the Channel-Picking strategies. For both populations, a difference was observed for the signal-to-noise ratios at 50% of the maximum recognition plateau in favour of the Fixed-Channel strategy. To conclude, in the most common signal-to-noise ratio conditions, a Fixed-Channel coding strategy may lead to better recognition percentages than a Channel-Picking strategy. Further studies are indicated to confirm this.

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