scholarly journals Word Recognition and Frequency Selectivity in Cochlear Implant Simulation: Effect of Channel Interaction

2021 ◽  
Vol 10 (4) ◽  
pp. 679
Author(s):  
Pierre-Antoine Cucis ◽  
Christian Berger-Vachon ◽  
Hung Thaï-Van ◽  
Ruben Hermann ◽  
Stéphane Gallego ◽  
...  
Keyword(s):  
Word Recognition ◽  
Spectral Resolution ◽  
Threshold Effect ◽  
Frequency Selectivity ◽  
Speech Processor ◽  
Tuning Curves ◽  
Channel Interaction ◽  
Individual Variations ◽  
Neural Excitation ◽  
The Individual

In cochlear implants (CI), spread of neural excitation may produce channel interaction. Channel interaction disturbs the spectral resolution and, among other factors, seems to impair speech recognition, especially in noise. In this study, two tests were performed with 20 adult normal-hearing (NH) subjects under different vocoded simulations. First, there was a measurement of word recognition in noise while varying the number of selected channels (4, 8, 12 or 16 maxima out of 20) and the degree of simulated channel interaction (“Low”, “Medium” and “High”). Then, there was an evaluation of spectral resolution function of the degree of simulated channel interaction, reflected by the sharpness (Q10dB) of psychophysical tuning curves (PTCs). The results showed a significant effect of the simulated channel interaction on word recognition but did not find an effect of the number of selected channels. The intelligibility decreased significantly for the highest degree of channel interaction. Similarly, the highest simulated channel interaction impaired significantly the Q10dB. Additionally, a strong intra-individual correlation between frequency selectivity and word recognition in noise was observed. Lastly, the individual changes in frequency selectivity were positively correlated with the changes in word recognition when the degree of interaction went from “Low” to “High”. To conclude, the degradation seen for the highest degree of channel interaction suggests a threshold effect on frequency selectivity and word recognition. The correlation between frequency selectivity and intelligibility in noise supports the hypothesis that PTCs Q10dB can account for word recognition in certain conditions. Moreover, the individual variations of performances observed among subjects suggest that channel interaction does not have the same effect on each individual. Finally, these results highlight the importance of taking into account subjects’ individuality and to evaluate channel interaction through the speech processor.

scholarly journals Effects of the Carrier Phrase on Word Recognition Performances by Younger and Older Listeners Using Two Stimulus Paradigms

2020 ◽  
Vol 31 (06) ◽  
pp. 412-441 ◽  
Author(s):  
Richard H. Wilson ◽  
Victoria A. Sanchez
Keyword(s):  
Word Recognition ◽  
Target Word ◽  
Speaker Recognition ◽  
Repeated Measures ◽  
Recognition Performance ◽  
Test Word ◽  
Root Mean Square Amplitude ◽  
Repeated Measures Design ◽  
The Mean ◽  
The Individual

Abstract Background In the 1950s, with monitored live voice testing, the vu meter time constant and the short durations and amplitude modulation characteristics of monosyllabic words necessitated the use of the carrier phrase amplitude to monitor (indirectly) the presentation level of the words. This practice continues with recorded materials. To relieve the carrier phrase of this function, first the influence that the carrier phrase has on word recognition performance needs clarification, which is the topic of this study. Purpose Recordings of Northwestern University Auditory Test No. 6 by two female speakers were used to compare word recognition performances with and without the carrier phrases when the carrier phrase and test word were (1) in the same utterance stream with the words excised digitally from the carrier (VA-1 speaker) and (2) independent of one another (VA-2 speaker). The 50-msec segment of the vowel in the target word with the largest root mean square amplitude was used to equate the target word amplitudes. Research Design A quasi-experimental, repeated measures design was used. Study Sample Twenty-four young normal-hearing adults (YNH; M = 23.5 years; pure-tone average [PTA] = 1.3-dB HL) and 48 older hearing loss listeners (OHL; M = 71.4 years; PTA = 21.8-dB HL) participated in two, one-hour sessions. Data Collection and Analyses Each listener had 16 listening conditions (2 speakers × 2 carrier phrase conditions × 4 presentation levels) with 100 randomized words, 50 different words by each speaker. Each word was presented 8 times (2 carrier phrase conditions × 4 presentation levels [YNH, 0- to 24-dB SL; OHL, 6- to 30-dB SL]). The 200 recorded words for each condition were randomized as 8, 25-word tracks. In both test sessions, one practice track was followed by 16 tracks alternated between speakers and randomized by blocks of the four conditions. Central tendency and repeated measures analyses of variance statistics were used. Results With the VA-1 speaker, the overall mean recognition performances were 6.0% (YNH) and 8.3% (OHL) significantly better with the carrier phrase than without the carrier phrase. These differences were in part attributed to the distortion of some words caused by the excision of the words from the carrier phrases. With the VA-2 speaker, recognition performances on the with and without carrier phrase conditions by both listener groups were not significantly different, except for one condition (YNH listeners at 8-dB SL). The slopes of the mean functions were steeper for the YNH listeners (3.9%/dB to 4.8%/dB) than for the OHL listeners (2.4%/dB to 3.4%/dB) and were <1%/dB steeper for the VA-1 speaker than for the VA-2 speaker. Although the mean results were clear, the variability in performance differences between the two carrier phrase conditions for the individual participants and for the individual words was striking and was considered in detail. Conclusion The current data indicate that word recognition performances with and without the carrier phrase (1) were different when the carrier phrase and target word were produced in the same utterance with poorer performances when the target words were excised from their respective carrier phrases (VA-1 speaker), and (2) were the same when the carrier phrase and target word were produced as independent utterances (VA-2 speaker).

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.

scholarly journals Using a Matlab Implemented Algorithm for UV-vis spectral Resolution for pka Determination and Multicomponent Analysis

2009 ◽  
Vol 4 ◽  
pp. ACI.S3499 ◽  
Author(s):  
Yotam Gonen ◽  
Giora Rytwo
Keyword(s):  
Spectral Resolution ◽  
Computer Code ◽  
Measured Spectrum ◽  
Visible Absorption Spectrum ◽  
Visible Absorption ◽  
Multicomponent Analysis ◽  
Value Estimation ◽  
Pka Determination ◽  
Uv Visible ◽  
The Individual

A Matlab implemented computer code for spectral resolution is presented. The code enables the user to resolve the UV-visible absorption spectrum of a mixture of up to 3 previously known components, to the individual components, thus, evaluating their quantities. The resolving procedure is based on searching the combination of the components which yields the spectrum which is the most similar (minimal RMSE) to the measured spectrum of the mixture. Examples of using the software for pKa value estimation and multicomponent analysis are presented and other implementations are suggested.

Bringing Computational Models of Word Naming Down to the Item Level

1997 ◽  
Vol 8 (6) ◽  
pp. 411-416 ◽  
Author(s):  
Daniel H. Spieler ◽  
David A. Balota
Keyword(s):  
Word Recognition ◽  
Computational Models ◽  
Predictive Power ◽  
Neighborhood Density ◽  
Word Naming ◽  
Connectionist Models ◽  
Item Level ◽  
The Individual ◽  
Level Performance ◽  
Naming Latencies

Early noncomputational models of word recognition have typically attempted to account for effects of categorical factors such as word frequency (high vs low) and spelling-to-sound regularity (regular vs irregular) More recent computational models that adhere to general connectionist principles hold the promise of being sensitive to underlying item differences that are only approximated by these categorical factors In contrast to earlier models, these connectionist models provide predictions of performance for individual items In the present study, we used the item-level estimates from two connectionist models (Plaut, McClelland, Seidenberg, & Patterson, 1996, Seidenberg & McClelland, 1989) to predict naming latencies on the individual items on which the models were trained The results indicate that the models capture, at best, slightly more variance than simple log frequency and substantially less than the combined predictive power of log frequency, neighborhood density, and orthographic length. The discussion focuses on the importance of examining the item-level performance of word-naming models and possible approaches that may improve the models' sensitivity to such item differences

Frequency selectivity in bird and man: A comparison among critical ratios, critical bands and psychophysical tuning curves

1979 ◽  
Vol 1 (4) ◽  
pp. 303-323 ◽  
Author(s):  
James C. Saunders ◽  
William F. Rintelmann ◽  
Gregory R. Bock
Keyword(s):  
Frequency Selectivity ◽  
Tuning Curves

scholarly journals Genetic homozygosity as a marker of smoking dependency

Genetika ◽  
2020 ◽  
Vol 52 (3) ◽  
pp. 1009-1019
Author(s):  
Slavko Brankovic ◽  
Dejan Nikolic ◽  
Dragoslav Marinkovic ◽  
Suzana Cvjeticanin
Keyword(s):  
Cross Sectional Study ◽  
Male Gender ◽  
Sectional Study ◽  
Cross Sectional ◽  
Male And Female ◽  
Mean Values ◽  
Individual Variations ◽  
Significant Difference ◽  
The Mean ◽  
The Individual

The aim of our study was to evaluate the morphogenetic variability as a marker of smoking dependency in adult smokers versus controls and to investigate the presence and the degree of morphogenetic variability difference between male and female smokers versus same gender controls. The cross-sectional study evaluated 241 smokers and 185 nonsmoker individuals as controls. We analyzed 17 homozygous recessive characteristics (HRC). There was a significant difference in the individual variations of 17 HRCs between the controls and smokers (??2=61.400, p<0.001; for females ??2=79.440, p<0.001; for males ??2=84.972, p<0.001). The mean values of HRCs significantly differed between smokers and controls (MV?SEM(Controls) -4.79?0.13, MV?SEM(Smokers) -5.70?0.12; p<0.001). For males, presence of 6/17 (35.29% genetic homozygosity) HRCs (OR=6.12) was to the certain degree predictor for smoking dependency. Higher degree of genetic homozygosity, changed variability and male gender, might be some among potential numerous factors that could have impact on smoking development and dependence.

scholarly journals Separation of the ‘blue’ and ‘green’ mechanisms of foveal vision by measurements of increment thresholds

1946 ◽  
Vol 133 (873) ◽  
pp. 418-434 ◽  
Keyword(s):  
Test Stimulus ◽  
High Intensity ◽  
Light Adaptation ◽  
Foveal Vision ◽  
Low Intensity ◽  
Individual Variations ◽  
Low Threshold ◽  
Intense Light ◽  
The Individual ◽  
Very High

The curve relating the smallest perceptible intensity of a blue test stimulus with the intensity of an orange conditioning field against which it is viewed shows a characteristic division into low- and high-intensity components, indicating the operation of two mechanisms of cone vision at the fovea. The justification for calling these ‘blue’ and ‘green’ mechanisms is taken from an earlier investigation (Stiles 1939). While most subjects show this division clearly, for some the low-intensity component is masked by the intrusion of rod vision. The correctness of this view is established by measurements made while the eye is recovering from an intense light adaptation. The individual variations of the sensitivities of the ‘green’ and ‘blue’ mechanisms in twenty subjects are assessed. Further evidence is obtained of an anomalously low threshold for the ‘blue’ mechanisms at very high conditioning fields of orange light.

scholarly journals Analysing the Relationship between Nutrition and the Microbial Composition of the Oral Biofilm—Insights from the Analysis of Individual Variability

Antibiotics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 479
Author(s):  
Kirstin Vach ◽  
Ali Al-Ahmad ◽  
Annette Anderson ◽  
Johan Peter Woelber ◽  
Lamprini Karygianni ◽  
...  
Keyword(s):  
Dietary Habits ◽  
Individual Variability ◽  
Oral Microbiota ◽  
Oral Diseases ◽  
Oral Biofilm ◽  
Microbial Composition ◽  
Mean Values ◽  
Individual Variations ◽  
The Individual ◽  
The Relationship

The influence of a change in nutrition on the oral microbiota are discussed in literature, but usually only changes of population mean values are reported. This paper introduces simple methods to also analyse and report the variability of patients’ reactions considering data from the culture analysis of oral biofilm. The framework was illustrated by an experimental study exposing eleven participants to different nutrition schemes in five consecutive phases. Substantial inter-individual variations in the individual reactions were observed. A new coherence index made it possible to identify 14 instances where the direction of individual changes tended to coincide with the direction of the mean change with more than 95% probability. The heterogeneity in variability across different bacteria species was limited. This allowed us to develop recommendations for sample sizes in future studies. For studies measuring the concentration change of bacteria as a reaction to nutrition change, the use of replications and analysis of the variability is recommended. In order to detect moderate effects of a change in nutrition on the concentration of single bacterial taxa, 30 participants with three repetitions are often adequate. Insights into the relationship between nutrition and the microbial composition can be helpful for the development of dietary habits that promote the establishment of a healthy microbial flora and can therefore prevent the initiation of oral diseases such as caries and periodontitis.

scholarly journals Psychometric Characteristics of Spanish Monosyllabic, Bisyllabic, and Trisyllabic Words for Use in Word-Recognition Protocols

2020 ◽  
Vol 31 (07) ◽  
pp. 531-546
Author(s):  
Mitzarie A. Carlo ◽  
Richard H. Wilson ◽  
Albert Villanueva-Reyes
Keyword(s):  
Word Recognition ◽  
Recognition Performance ◽  
Normal Hearing ◽  
Current Data ◽  
Hearing Level ◽  
Psychometric Characteristics ◽  
Plural Form ◽  
Individual Word ◽  
The Mean ◽  
The Individual

Abstract Background English materials for speech audiometry are well established. In Spanish, speech-recognition materials are not standardized with monosyllables, bisyllables, and trisyllables used in word-recognition protocols. Purpose This study aimed to establish the psychometric characteristics of common Spanish monosyllabic, bisyllabic, and trisyllabic words for potential use in word-recognition procedures. Research Design Prospective descriptive study. Study Sample Eighteen adult Puerto Ricans (M = 25.6 years) with normal hearing [M = 7.8-dB hearing level (HL) pure-tone average] were recruited for two experiments. Data Collection and Analyses A digital recording of 575 Spanish words was created (139 monosyllables, 359 bisyllables, and 77 trisyllables), incorporating materials from a variety of Spanish word-recognition lists. Experiment 1 (n = 6) used 25 randomly selected words from each of the three syllabic categories to estimate the presentation level ranges needed to obtain recognition performances over the 10 to 90% range. In Experiment 2 (n = 12) the 575 words were presented over five 1-hour sessions using presentation levels from 0- to 30-dB HL in 5-dB steps (monosyllables), 0- to 25-dB HL in 5-dB steps (bisyllables), and −3- to 17-dB HL in 4-dB steps (trisyllables). The presentation order of both the words and the presentation levels were randomized for each listener. The functions for each listener and each word were fit with polynomial equations from which the 50% points and slopes at the 50% point were calculated. Results The mean 50% points and slopes at 50% were 8.9-dB HL, 4.0%/dB (monosyllables), 6.9-dB HL, 5.1%/dB (bisyllables), and 1.4-dB HL, 6.3%/dB (trisyllables). The Kruskal–Wallis test with Mann–Whitney U post-hoc analysis indicated that the mean 50% points and slopes at the 50% points of the individual word functions were significantly different among the syllabic categories. Although significant differences were observed among the syllabic categories, substantial overlap was noted in the individual word functions, indicating that the psychometric characteristics of the words were not dictated exclusively by the syllabic number. Influences associated with word difficulty, word familiarity, singular and plural form words, phonetic stress patterns, and gender word patterns also were evaluated. Conclusion The main finding was the direct relation between the number of syllables in a word and word-recognition performance. In general, words with more syllables were more easily recognized; there were, however, exceptions. The current data from young adults with normal hearing established the psychometric characteristics of the 575 Spanish words on which the formulation of word lists for both threshold and suprathreshold measures of word-recognition abilities in quiet and in noise and other word-recognition protocols can be based.

Relation between Frequency Selectivity and Speech Perception Following Glycerol-Induced Cochlear Changes

1985 ◽  
Vol 50 (4) ◽  
pp. 372-377 ◽  
Author(s):  
Patricia G. Stelmachowicz ◽  
Dawna E. Johnson ◽  
Lori L. Larson ◽  
Patrick E. Brookhouser
Keyword(s):  
Hearing Loss ◽  
Speech Perception ◽  
Sensorineural Hearing Loss ◽  
Frequency Selectivity ◽  
Auditory Threshold ◽  
Sensorineural Hearing ◽  
Frequency Resolution ◽  
Intersubject Variability ◽  
Tuning Curves ◽  
Clear Relation

Changes in auditory threshold, psychophysical tuning curves, and speech perception (in both quiet and noise) were monitored over a 3-hr period following the ingestion of glycerol. All listeners had sensorineural hearing loss secondary to Menière's disease. Findings were characterized by large intersubject variability and in general did not show a clear relation between changes in threshold, frequency resolution, and speech perception.

Sign in / Sign up

Export Citation Format

Share Document