scholarly journals Assessing the relationship between neural health measures and speech performance with simultaneous electric stimulation in cochlear implant listeners

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261295
Author(s):  
Florian Langner ◽  
Julie G. Arenberg ◽  
Andreas Büchner ◽  
Waldo Nogueira
Keyword(s):  
Cochlear Implant ◽  
Growth Function ◽  
Speech Understanding ◽  
Signal To Noise ◽  
Indirect Measure ◽  
Processing Strategies ◽  
Speech Performance ◽  
The Difference ◽  
The Relationship ◽  
Offset Effect

Objectives The relationship between electrode-nerve interface (ENI) estimates and inter-subject differences in speech performance with sequential and simultaneous channel stimulation in adult cochlear implant listeners were explored. We investigated the hypothesis that individuals with good ENIs would perform better with simultaneous compared to sequential channel stimulation speech processing strategies than those estimated to have poor ENIs. Methods Fourteen postlingually deaf implanted cochlear implant users participated in the study. Speech understanding was assessed with a sentence test at signal-to-noise ratios that resulted in 50% performance for each user with the baseline strategy F120 Sequential. Two simultaneous stimulation strategies with either two (Paired) or three sets of virtual channels (Triplet) were tested at the same signal-to-noise ratio. ENI measures were estimated through: (I) voltage spread with electrical field imaging, (II) behavioral detection thresholds with focused stimulation, and (III) slope (IPG slope effect) and 50%-point differences (dB offset effect) of amplitude growth functions from electrically evoked compound action potentials with two interphase gaps. Results A significant effect of strategy on speech understanding performance was found, with Triplets showing a trend towards worse speech understanding performance than sequential stimulation. Focused thresholds correlated positively with the difference required to reach most comfortable level (MCL) between Sequential and Triplet strategies, an indirect measure of channel interaction. A significant offset effect (difference in dB between 50%-point for higher eCAP growth function slopes with two IPGs) was observed. No significant correlation was observed between the slopes for the two IPGs tested. None of the measures used in this study correlated with the differences in speech understanding scores between strategies. Conclusions The ENI measure based on behavioral focused thresholds could explain some of the difference in MCLs, but none of the ENI measures could explain the decrease in speech understanding with increasing pairs of simultaneously stimulated electrodes in processing strategies.

scholarly journals Using a cochlear implant processor as contralateral routing of signals device in unilateral cochlear implant recipients

2021 ◽  
Author(s):  
Tom Gawliczek ◽  
Jérémie Guignard ◽  
Christoph Schmid ◽  
Wilhelm Wimmer ◽  
Marco Caversaccio ◽  
...  
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Auditory Information ◽  
Significant Gain ◽  
Subjective Ratings ◽  
Summation Effect ◽  
Processing Strategies ◽  
Acoustic Chamber ◽  
The Difference ◽  
To Receive

Abstract Purpose In unilateral cochlear implant (CI) recipients, a contralateral routing of signals (CROS) device enables to receive auditory information from the unaided side. This study investigates the feasibility as well as subjective and objective benefits of using a CI processor as a CROS device in unilateral CI recipients. Methods This is a single-center, prospective cohort study. First, we tested the directionality of the CROS processor in an acoustic chamber. Second, we examined the difference of speech perception in quiet and in noise in ten unilateral CI recipients with and without the CROS processor. Third, subjective ratings with the CROS processor were evaluated according to the Client Oriented Scale of Improvement Questionnaire. Results There was a time delay between the two devices of 3 ms. Connection of the CROS processor led to a summation effect of 3 dB as well as a more constant amplification along all azimuths. Speech perception in quiet showed an increased word recognition score at 50 dB (mean improvement 7%). In noise, the head shadow effect could be mitigated with significant gain in speech perception (mean improvement 8.4 dB). This advantage was reversed in unfavorable listening situations, where the CROS device considerably amplified the noise (mean:  – 4.8 dB). Subjectively, patients who did not normally wear a hearing aid on the non-CI side were satisfied with the CROS device. Conclusions The connection and synchronization of a CI processor as a CROS device is technically feasible and the signal processing strategies of the device can be exploited. In contra-laterally unaided patients, a subjective benefit can be achieved when wearing the CROS processor.

Examining the Relationship Between Speech Recognition and a Spectral–Temporal Test With a Mixed Group of Hearing Aid and Cochlear Implant Users

2021 ◽  
Vol 64 (3) ◽  
pp. 1073-1080
Author(s):  
Justin M. Aronoff ◽  
Leah Duitsman ◽  
Deanna K. Matusik ◽  
Senad Hussain ◽  
Elise Lippmann
Keyword(s):  
Cochlear Implant ◽  
Cochlear Implants ◽  
Hearing Aids ◽  
Significant Relationship ◽  
Signal To Noise Ratio ◽  
Hearing Aid ◽  
Mixed Group ◽  
Signal To Noise ◽  
Hearing Devices ◽  
The Relationship

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.

PREDICTING SPEECH INTELLIGIBILITY FROM A SELECTIVE ATTENTION DECODING PARADIGM IN COCHLEAR IMPLANT USERS

2021 ◽  
Author(s):  
Waldo Nogueira ◽  
Hanna Dolhopiatenko
Keyword(s):  
Selective Attention ◽  
Cochlear Implant ◽  
Correlation Coefficient ◽  
Speech Intelligibility ◽  
Correlation Coefficients ◽  
Speech Understanding ◽  
Care Needs ◽  
The Difference ◽  
Envelope Reconstruction ◽  
Correlation Trend

Objectives: Electroencephalography (EEG) can be used to decode selective attention in cochlear implant (CI) users. This work investigates if selective attention to an attended speech source in the presence of a concurrent speech source can predict speech understanding in CI users. Approach: CI users were instructed to attend to one out of two speech streams while EEG was recorded. Both speech streams were presented to the same ear and at different signal to interference ratios (SIRs). Speech envelope reconstruction of the to-be-attended speech from EEG was obtained by training decoders using regularized least squares. The correlation coefficient between the reconstructed and the attended (ρ_(A_SIR )) and between the reconstructed and the unattended (ρ_(U_SIR )) speech stream at each SIR was computed. Main Results: Selective attention decoding in CI users is possible even if both speech streams are presented monaurally. A significant effect of SIR on the correlation coefficient to the attended signal ρ_(A_SIR ), as well as on the difference correlation coefficients ρ_(A_SIR )-ρ_(U_SIR ) and ρ_(A_SIR )-ρ_(U_(-SIR) ) was observed, but not on the unattended correlation coefficient ρ_(U_SIR ). Finally, the results show a significant correlation between speech understanding performance and the correlation coefficients ρ_(A_SIR-) ρ_(U_SIR ) or -ρ_(U_SIR ) across subjects. Moreover, the difference correlation coefficient ρ_(A_SIR )-ρ_(U_(-SIR) ), which is less affected by the CI electrical artifact, presented a correlation trend with speech understanding performance. Significance: Selective attention decoding in CI users is possible, however care needs to be taken with the CI artifact and the speech material used to train the decoders. Even if only a small correlation trend between selective attention decoding and speech understanding was observed, these results are important for future development of objective speech understanding measures for CI users.

scholarly journals Behavioral Measures of Temporal Processing and Speech Perception in Cochlear Implant Users

2016 ◽  
Vol 27 (09) ◽  
pp. 701-713 ◽  
Author(s):  
Chelsea Blankenship ◽  
Fawen Zhang ◽  
Robert Keith
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Recognition Test ◽  
Temporal Processing ◽  
Acoustic Stimulation ◽  
Gap Detection ◽  
Temporal Acuity ◽  
Significant Difference ◽  
The Difference ◽  
The Relationship

Background: Although most cochlear implant (CI) users achieve improvements in speech perception, there is still a wide variability in speech perception outcomes. There is a growing body of literature that supports the relationship between individual differences in temporal processing and speech perception performance in CI users. Previous psychophysical studies have emphasized the importance of temporal acuity for overall speech perception performance. Measurement of gap detection thresholds (GDTs) is the most common measure currently used to assess temporal resolution. However, most GDT studies completed with CI participants used direct electrical stimulation not acoustic stimulation and they used psychoacoustic research paradigms that are not easy to administer clinically. Therefore, it is necessary to determine if the variance in GDTs assessed with clinical measures of temporal processing such as the Randomized Gap Detection Test (RGDT) can be used to explain the variability in speech perception performance. Purpose: The primary goal of this study was to investigate the relationship between temporal processing and speech perception performance in CI users. Research Design: A correlational study investigating the relationship between behavioral GDTs (assessed with the RGDT or the Expanded Randomized Gap Detection Test) and commonly used speech perception measures (assessed with the Speech Recognition Test [SRT], Central Institute for the Deaf W-22 Word Recognition Test [W-22], Consonant-Nucleus-Consonant Test [CNC], Arizona Biomedical Sentence Recognition Test [AzBio], Bamford–Kowal–Bench Speech-in-Noise Test [BKB-SIN]). Study Sample: Twelve postlingually deafened adult CI users (24–83 yr) and ten normal-hearing (NH; 22–30 yr) adults participated in the study. Data Collection and Analysis: The data were collected in a sound-attenuated test booth. After measuring pure-tone thresholds, GDTs and speech perception performance were measured. The difference in performance between-participant groups on the aforementioned tests, as well as the correlation between GDTs and speech perception performance was examined. The correlations between participants’ biologic factors, performance on the RGDT and speech perception measures were also explored. Results: Although some CI participants performed as well as the NH listeners, the majority of the CI participants displayed temporal processing impairments (GDTs > 20 msec) and poorer speech perception performance than NH participants. A statistically significant difference was found between the NH and CI test groups in GDTs and some speech tests (SRT, W-22, and BKB-SIN). For the CI group, there were significant correlations between GDTs and some measures of speech perception (CNC Phoneme, AzBio, BKB-SIN); however, no significant correlations were found between biographic factors and GDTs or speech perception performance. Conclusions: Results support the theory that the variability in temporal acuity in CI users contributes to the variability in speech performance. Results also indicate that it is reasonable to use the clinically available RGDT to identify CI users with temporal processing impairments for further appropriate rehabilitation.

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.

Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 260-261
Author(s):  
Robert M. Glaeser
Keyword(s):  
High Resolution ◽  
Particle Flux ◽  
Unit Area ◽  
Signal To Noise ◽  
Resolution Image ◽  
High Resolution Image ◽  
Pass Through ◽  
Counting Statistics ◽  
The Relationship ◽  
Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

Grain separation enhanced magnetic coercivity in Pt/Co multilayers.

1993 ◽  
Vol 51 ◽  
pp. 1038-1039 ◽  
Author(s):  
G.A. Bertero ◽  
R. Sinclair
Keyword(s):  
Remanent Magnetization ◽  
Strong Influence ◽  
Uniaxial Anisotropy ◽  
Magnetic Coupling ◽  
Recording Media ◽  
Magnetic Media ◽  
Signal To Noise ◽  
Out Of Plane ◽  
Longitudinal Recording ◽  
The Relationship

Pt/Co multilayers displaying perpendicular (out-of-plane) magnetic anisotropy and 100% perpendicular remanent magnetization are strong candidates as magnetic media for the next generation of magneto-optic recording devices. The magnetic coercivity, Hc, and uniaxial anisotropy energy, Ku, are two important materials parameters, among others, in the quest to achieving higher recording densities with acceptable signal to noise ratios (SNR). The relationship between Ku and Hc in these films is not a simple one since features such as grain boundaries, for example, can have a strong influence on Hc but affect Ku only in a secondary manner. In this regard grain boundary separation provides a way to minimize the grain-to-grain magnetic coupling which is known to result in larger coercivities and improved SNR as has been discussed extensively in the literature for conventional longitudinal recording media.We present here results from the deposition of two Pt/Co/Tb multilayers (A and B) which show significant differences in their coercive fields.

Comparison of In-the-Ear and Over-the-Ear Hearing Aid Fittings

1986 ◽  
Vol 51 (4) ◽  
pp. 362-369 ◽  
Author(s):  
Donna M. Risberg ◽  
Robyn M. Cox
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Comparative Evaluation ◽  
Speech Intelligibility ◽  
Hearing Aid ◽  
Hearing Aid Fitting ◽  
The Difference ◽  
Functional Gain ◽  
The Relationship

A custom in-the-ear (ITE) hearing aid fitting was compared to two over-the-ear (OTE) hearing aid fittings for each of 9 subjects with mild to moderately severe hearing losses. Speech intelligibility via the three instruments was compared using the Speech Intelligibility Rating (SIR) test. The relationship between functional gain and coupler gain was compared for the ITE and the higher rated OTE instruments. The difference in input received at the microphone locations of the two types of hearing aids was measured for 10 different subjects and compared to the functional gain data. It was concluded that (a) for persons with mild to moderately severe hearing losses, appropriately adjusted custom ITE fittings typically yield speech intelligibility that is equal to the better OTE fitting identified in a comparative evaluation; and (b) gain prescriptions for ITE hearing aids should be adjusted to account for the high-frequency emphasis associated with in-the-concha microphone placement.

Relationship between total plasma homocysteine and the risk of aneurysms – a meta-analysis

VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  
Keyword(s):  
Large Scale ◽  
Meta Analysis ◽  
Single Species ◽  
Total Plasma ◽  
Control Groups ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
The Difference ◽  
The Relationship ◽  
Healthy Participants

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.

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