scholarly journals Loudness Functions and Binaural Loudness Summation in Bilateral Cochlear Implant Users

2017 ◽  
Vol 42 (3) ◽  
pp. 351-364
Author(s):  
Monika Kordus ◽  
Jan Żera
Keyword(s):  
Individual Differences ◽  
Cochlear Implant ◽  
Stimulus Presentation ◽  
Normal Hearing ◽  
Control Group ◽  
Large Individual ◽  
Experimental Conditions ◽  
Large Variability ◽  
Bilateral Cochlear Implant ◽  
Loudness Summation

AbstractLoudness functions and binaural loudness summation was investigated in acoustically stimulated bilaterally implanted cochlear implant users. The study was aimed at evaluating growth of loudness functions and binaural loudness summation in cochlear implant subjects as a function of stimulus presentation level at different frequencies. Loudness was assessed using a rating procedure on a scale of 0 to 100. Three experimental conditions were tested: monaural right, monaural left and binaural, each with bands of noise with center frequencies of 0.25, 1, and 4 kHz. Fifteen implanted and five normal-hearing subjects (control group) participated in the experiments. Results demonstrated large variability in the slopes of the loudness functions and the presence of loudness summation in bilateral cochlear implant users, with large individual differences among subjects.

scholarly journals Alpha EEG Frontal Asymmetries during Audiovisual Perception in Cochlear Implant Users

2015 ◽  
Vol 54 (06) ◽  
pp. 500-504 ◽  
Author(s):  
A. G. Maglione ◽  
A. Scorpecci ◽  
P. Malerba ◽  
P. Marsella ◽  
S. Giannantonio ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Alpha Rhythm ◽  
Normal Hearing ◽  
Experimental Conditions ◽  
Audiovisual Perception ◽  
Audiovisual Stimuli ◽  
The Difference ◽  
Eeg Alpha ◽  
The One ◽  
Hearing Children

SummaryObjectives: The aim of the present study is to investigate the variations of the electroencephalographic (EEG) alpha rhythm in order to measure the appreciation of bilateral and unilateral young cochlear implant users during the observation of a musical cartoon. The cartoon has been modified for the generation of three experimental conditions: one with the original audio, another one with a distorted sound and, finally, a mute version.Methods: The EEG data have been recorded during the observation of the cartoons in the three experimental conditions. The frontal alpha EEG imbalance has been calculated as a measure of motivation and pleasantness to be compared across experimental populations and conditions.Results: The EEG frontal imbalance of the alpha rhythm showed significant variations during the perception of the different cartoons. In particular, the pattern of activation of normal-hearing children is very similar to the one elicited by the bilateral implanted patients. On the other hand, results related to the unilateral subjects do not present significant variations of the imbalance index across the three cartoons.Conclusion: The presented results suggest that the unilateral patients could not appreciate the difference in the audio format as well as bilaterally implanted and normal hearing subjects. The frontal alpha EEG imbalance is a useful tool to detect the differences in the appreciation of audiovisual stimuli in cochlear implant patients.

scholarly journals Spatial Speech-in-Noise Performance in Bimodal and Single-Sided Deaf Cochlear Implant Users

2019 ◽  
Vol 23 ◽  
pp. 233121651985831 ◽  
Author(s):  
Ben Williges ◽  
Thomas Wesarg ◽  
Lorenz Jung ◽  
Leontien I. Geven ◽  
Andreas Radeloff ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Normal Hearing ◽  
Head Movements ◽  
Control Group ◽  
Noise Performance ◽  
Speech In Noise ◽  
Speech Reception ◽  
Patient Groups ◽  
Speech Reception Thresholds ◽  
Binaural Listening

This study compared spatial speech-in-noise performance in two cochlear implant (CI) patient groups: bimodal listeners, who use a hearing aid contralaterally to support their impaired acoustic hearing, and listeners with contralateral normal hearing, i.e., who were single-sided deaf before implantation. Using a laboratory setting that controls for head movements and that simulates spatial acoustic scenes, speech reception thresholds were measured for frontal speech-in-stationary noise from the front, the left, or the right side. Spatial release from masking (SRM) was then extracted from speech reception thresholds for monaural and binaural listening. SRM was found to be significantly lower in bimodal CI than in CI single-sided deaf listeners. Within each listener group, the SRM extracted from monaural listening did not differ from the SRM extracted from binaural listening. In contrast, a normal-hearing control group showed a significant improvement in SRM when using two ears in comparison to one. Neither CI group showed a binaural summation effect; that is, their performance was not improved by using two devices instead of the best monaural device in each spatial scenario. The results confirm a “listening with the better ear” strategy in the two CI patient groups, where patients benefited from using two ears/devices instead of one by selectively attending to the better one. Which one is the better ear, however, depends on the spatial scenario and on the individual configuration of hearing loss.

scholarly journals Identification of Vowel Length, Word Stress, and Compound Words and Phrases by Postlingually Deafened Cochlear Implant Listeners

2013 ◽  
Vol 24 (09) ◽  
pp. 879-890 ◽  
Author(s):  
David Morris ◽  
Lennart Magnusson ◽  
Andrew Faulkner ◽  
Radoslava Jönsson ◽  
Holger Juul
Keyword(s):  
Cochlear Implant ◽  
Oral Language ◽  
Normal Hearing ◽  
Acoustic Properties ◽  
Control Group ◽  
Compound Words ◽  
Noise Condition ◽  
Vowel Length ◽  
Word Stress ◽  
Prosodic Cues

Background: The accurate perception of prosody assists a listener in deriving meaning from natural speech. Few studies have addressed the ability of cochlear implant (CI) listeners to perceive the brief duration prosodic cues involved in contrastive vowel length, word stress, and compound word and phrase identification. Purpose: To compare performance in the perception of brief duration prosodic contrasts by CI participants and a control group of normal hearing participants. This study investigated the ability to perceive these cues in quiet and noise conditions, and to identify auditory perceptual factors that might predict prosodic perception in the CI group. Prosodic perception was studied both in noise and quiet because noise is a pervasive feature of everyday environments. Research Design: A quasi-experimental correlation design was employed. Study Sample: Twenty-one CI recipients participated along with a control group of 10 normal hearing participants. All CI participants were unilaterally implanted adults who had considerable experience with oral language prior to implantation. Data Collection and Analysis: Speech identification testing measured the participants' ability to identify word stress, vowel length, and compound words or phrases all of which were presented with minimal-pair response choices. Tests were performed in quiet and in speech-spectrum shaped noise at a 10 dB signal-to-noise ratio. Also, discrimination thresholds for four acoustic properties of a synthetic vowel were measured as possible predictors of prosodic perception. Testing was carried out during one session, and participants used their clinically assigned speech processors. Results: The CI group could not identify brief prosodic cues as well as the control group, and their performance decreased significantly in the noise condition. Regression analysis showed that the discrimination of intensity predicted performance on the prosodic tasks. The performance decline measured with the older participants meant that age also emerged as a predictor. Conclusions: This study provides a portrayal of CI recipients' ability to perceive brief prosodic cues. This is of interest in the preparation of rehabilitation materials used in training and in developing realistic expectations for potential CI candidates.

Development of Basic Auditory Discrimination in Preschool Children

1993 ◽  
Vol 4 (2) ◽  
pp. 104-107 ◽  
Author(s):  
Janet K. Jensen ◽  
Donna L. Neff
Keyword(s):  
Individual Differences ◽  
Preschool Children ◽  
Age Groups ◽  
Duration Discrimination ◽  
Normal Hearing ◽  
Auditory Discrimination ◽  
Large Individual ◽  
Intensity Discrimination ◽  
Hearing Children

Intensity (loudness), frequency (pitch), and duration discrimination were examined in 41 normal-hearing children, aged 4 to 6 years, and 9 adults. A second study retested 25 of the youngest children 12 to 18 months later. Intensity discrimination showed the least improvement with age and was adultlike by age 5 for most of the children. In contrast, frequency and duration discrimination showed highly significant improvement with age, hut remained poorer than adults' discrimination for many 6-year-olds. Large individual differences were observed within alt tasks and age groups.

Effect of Synchronized Linked Band Selection on Speech Intelligibility of Bilateral Cochlear Implant Users

2020 ◽  
Author(s):  
Tom Gajęcki ◽  
Waldo Nogueira
Keyword(s):  
Electrical Stimulation ◽  
Cochlear Implant ◽  
Background Noise ◽  
Speech Intelligibility ◽  
Signal To Noise Ratio ◽  
Normal Hearing ◽  
Band Selection ◽  
Signal To Noise ◽  
Intelligibility Test ◽  
Bilateral Cochlear Implant

Normal hearing listeners have the ability to exploit the audio input perceived by each ear to extract target information in challenging listening scenarios. Bilateral cochlear implant (BiCI) users, however, do not benefit as much as normal hearing listeners do from a bilateral input. In this study, we investigate the effect that bilaterally linked band selection, bilaterally synchronized electrical stimulation and ideal binary masks (IdBMs) have on the ability of 10 BiCIs to understand speech in background noise. The performance was assessed through a sentence-based speech intelligibility test, in a scenario where the speech signal was presented from the front and the interfering noise from one side. The linked band selection relies on the most favorable signal-to-noise-ratio (SNR) ear, which will select the bands to be stimulated for both CIs. Results show that no benefit from adding a second CI to the most favorable SNR side was achieved for any of the tested bilateral conditions. However, when using both devices, speech perception results show that performing linked band selection, besides delivering bilaterally synchronized electrical stimulation, leads to an improvement compared to standard clinical setups. Moreover, the outcomes of this work show that by applying IdBMs, subjects achieve speech intelligibility scores similar to the ones without background noise.

scholarly journals Decoding Selective Attention in Normal Hearing Listeners and Bilateral Cochlear Implant Users With Concealed Ear EEG

2019 ◽  
Vol 13 ◽  
Author(s):  
Waldo Nogueira ◽  
Hanna Dolhopiatenko ◽  
Irina Schierholz ◽  
Andreas Büchner ◽  
Bojana Mirkovic ◽  
...  
Keyword(s):  
Selective Attention ◽  
Cochlear Implant ◽  
Normal Hearing ◽  
Bilateral Cochlear Implant

scholarly journals Approximations to the Voice of a Cochlear Implant: Explorations With Single-Sided Deaf Listeners

2020 ◽  
Vol 24 ◽  
pp. 233121652092007
Author(s):  
Michael F. Dorman ◽  
Sarah Cook Natale ◽  
Leslie Baxter ◽  
Daniel M. Zeitler ◽  
Matthew L. Carlson ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Normal Hearing ◽  
Large Individual ◽  
Electrode Arrays ◽  
Formant Frequencies ◽  
Low Pass ◽  
Small Set ◽  
F0 Contour ◽  
Spectral Smearing ◽  
Electrode Insertion

Fourteen single-sided deaf listeners fit with an MED-EL cochlear implant (CI) judged the similarity of clean signals presented to their CI and modified signals presented to their normal-hearing ear. The signals to the normal-hearing ear were created by (a) filtering, (b) spectral smearing, (c) changing overall fundamental frequency (F0), (d) F0 contour flattening, (e) changing formant frequencies, (f) altering resonances and ring times to create a metallic sound quality, (g) using a noise vocoder, or (h) using a sine vocoder. The operations could be used singly or in any combination. On a scale of 1 to 10 where 10 was a complete match to the sound of the CI, the mean match score was 8.8. Over half of the matches were 9.0 or higher. The most common alterations to a clean signal were band-pass or low-pass filtering, spectral peak smearing, and F0 contour flattening. On average, 3.4 operations were used to create a match. Upshifts in formant frequencies were implemented most often for electrode insertion angles less than approximately 500°. A relatively small set of operations can produce signals that approximate the sound of the MED-EL CI. There are large individual differences in the combination of operations needed. The sound files in Supplemental Material approximate the sound of the MED-EL CI for patients fit with 28-mm electrode arrays.

scholarly journals Head Shadow, Summation, and Squelch in Bilateral Cochlear-Implant Users With Linked Automatic Gain Controls

2021 ◽  
Vol 25 ◽  
pp. 233121652110181
Author(s):  
Taylor A. Bakal ◽  
Kristina DeRoy Milvae ◽  
Chen Chen ◽  
Matthew J. Goupell
Keyword(s):  
Cochlear Implant ◽  
Functional Performance ◽  
Binaural Hearing ◽  
Normal Hearing ◽  
Functional Asymmetry ◽  
Speech Understanding ◽  
Speech Understanding In Noise ◽  
Bilateral Cochlear Implant ◽  
Automatic Gain Controls ◽  
Interaural Level Differences

Speech understanding in noise is poorer in bilateral cochlear-implant (BICI) users compared to normal-hearing counterparts. Independent automatic gain controls (AGCs) may contribute to this because adjusting processor gain independently can reduce interaural level differences that BICI listeners rely on for bilateral benefits. Bilaterally linked AGCs may improve bilateral benefits by increasing the magnitude of interaural level differences. The effects of linked AGCs on bilateral benefits (summation, head shadow, and squelch) were measured in nine BICI users. Speech understanding for a target talker at 0° masked by a single talker at 0°, 90°, or −90° azimuth was assessed under headphones with sentences at five target-to-masker ratios. Research processors were used to manipulate AGC type (independent or linked) and test ear (left, right, or both). Sentence recall was measured in quiet to quantify individual interaural asymmetry in functional performance. The results showed that AGC type did not significantly change performance or bilateral benefits. Interaural functional asymmetries, however, interacted with ear such that greater summation and squelch benefit occurred when there was larger functional asymmetry, and interacted with interferer location such that smaller head shadow benefit occurred when there was larger functional asymmetry. The larger benefits for those with larger asymmetry were driven by improvements from adding a better-performing ear, rather than a true binaural-hearing benefit. In summary, linked AGCs did not significantly change bilateral benefits in cases of speech-on-speech masking with a single-talker masker, but there was also no strong detriment across a range of target-to-masker ratios, within a small and diverse BICI listener population.

Sign in / Sign up

Export Citation Format

Share Document