scholarly journals Cortical Processing of Frequency Changes Reflected by the Acoustic Change Complex in Adult Cochlear Implant Users

2018 ◽  
Vol 23 (3) ◽  
pp. 152-164 ◽  
Author(s):  
Chun Liang ◽  
Lisa M. Houston ◽  
Ravi N. Samy ◽  
Lamiaa Mohamed Ibrahim Abedelrehim ◽  
Fawen Zhang

The purpose of this study was to examine neural substrates of frequency change detection in cochlear implant (CI) recipients using the acoustic change complex (ACC), a type of cortical auditory evoked potential elicited by acoustic changes in an ongoing stimulus. A psychoacoustic test and electroencephalographic recording were administered in 12 postlingually deafened adult CI users. The stimuli were pure tones containing different magnitudes of upward frequency changes. Results showed that the frequency change detection threshold (FCDT) was 3.79% in the CI users, with a large variability. The ACC N1’ latency was significantly correlated with the FCDT and the clinically collected speech perception score. The results suggested that the ACC evoked by frequency changes can serve as a useful objective tool in assessing frequency change detection capability and predicting speech perception performance in CI users.

2021 ◽  
Vol 15 ◽  
Author(s):  
Kelli McGuire ◽  
Gabrielle M. Firestone ◽  
Nanhua Zhang ◽  
Fawen Zhang

One of the biggest challenges that face cochlear implant (CI) users is the highly variable hearing outcomes of implantation across patients. Since speech perception requires the detection of various dynamic changes in acoustic features (e.g., frequency, intensity, timing) in speech sounds, it is critical to examine the ability to detect the within-stimulus acoustic changes in CI users. The primary objective of this study was to examine the auditory event-related potential (ERP) evoked by the within-stimulus frequency changes (F-changes), one type of the acoustic change complex (ACC), in adult CI users, and its correlation to speech outcomes. Twenty-one adult CI users (29 individual CI ears) were tested with psychoacoustic frequency change detection tasks, speech tests including the Consonant-Nucleus-Consonant (CNC) word recognition, Arizona Biomedical Sentence Recognition in quiet and noise (AzBio-Q and AzBio-N), and the Digit-in-Noise (DIN) tests, and electroencephalographic (EEG) recordings. The stimuli for the psychoacoustic tests and EEG recordings were pure tones at three different base frequencies (0.25, 1, and 4 kHz) that contained a F-change at the midpoint of the tone. Results showed that the frequency change detection threshold (FCDT), ACC N1′ latency, and P2′ latency did not differ across frequencies (p > 0.05). ACC N1′-P2 amplitude was significantly larger for 0.25 kHz than for other base frequencies (p < 0.05). The mean N1′ latency across three base frequencies was negatively correlated with CNC word recognition (r = −0.40, p < 0.05) and CNC phoneme (r = −0.40, p < 0.05), and positively correlated with mean FCDT (r = 0.46, p < 0.05). The P2′ latency was positively correlated with DIN (r = 0.47, p < 0.05) and mean FCDT (r = 0.47, p < 0.05). There was no statistically significant correlation between N1′-P2′ amplitude and speech outcomes (all ps > 0.05). Results of this study indicated that variability in CI speech outcomes assessed with the CNC, AzBio-Q, and DIN tests can be partially explained (approximately 16–21%) by the variability of cortical sensory encoding of F-changes reflected by the ACC.


2019 ◽  
Vol 379 ◽  
pp. 12-20 ◽  
Author(s):  
Fawen Zhang ◽  
Gabrielle Underwood ◽  
Kelli McGuire ◽  
Chun Liang ◽  
David R. Moore ◽  
...  

2010 ◽  
Vol 10 ◽  
pp. 329-339 ◽  
Author(s):  
Torsten Rahne ◽  
Michael Ziese ◽  
Dorothea Rostalski ◽  
Roland Mühler

This paper describes a logatome discrimination test for the assessment of speech perception in cochlear implant users (CI users), based on a multilingual speech database, the Oldenburg Logatome Corpus, which was originally recorded for the comparison of human and automated speech recognition. The logatome discrimination task is based on the presentation of 100 logatome pairs (i.e., nonsense syllables) with balanced representations of alternating “vowel-replacement” and “consonant-replacement” paradigms in order to assess phoneme confusions. Thirteen adult normal hearing listeners and eight adult CI users, including both good and poor performers, were included in the study and completed the test after their speech intelligibility abilities were evaluated with an established sentence test in noise. Furthermore, the discrimination abilities were measured electrophysiologically by recording the mismatch negativity (MMN) as a component of auditory event-related potentials. The results show a clear MMN response only for normal hearing listeners and CI users with good performance, correlating with their logatome discrimination abilities. Higher discrimination scores for vowel-replacement paradigms than for the consonant-replacement paradigms were found. We conclude that the logatome discrimination test is well suited to monitor the speech perception skills of CI users. Due to the large number of available spoken logatome items, the Oldenburg Logatome Corpus appears to provide a useful and powerful basis for further development of speech perception tests for CI users.


2021 ◽  
Vol 11 (2) ◽  
pp. 220-226
Author(s):  
Yew-Song Cheng ◽  
Mario A. Svirsky

The presence of spiral ganglion cells (SGCs) is widely accepted to be a prerequisite for successful speech perception with a cochlear implant (CI), because SGCs provide the only known conduit between the implant electrode and the central auditory system. By extension, it has been hypothesized that the number of SGCs might be an important factor in CI outcomes. An impressive body of work has been published on findings from the laborious process of collecting temporal bones from CI users and counting the number of SGCs to correlate those numbers with speech perception scores, but the findings thus far have been conflicting. We performed a meta-analysis of all published studies with the hope that combining existing data may help us reach a more definitive conclusion about the relationship between SGC count and speech perception scores in adults.


1993 ◽  
Vol 94 (6) ◽  
pp. 3178-3189 ◽  
Author(s):  
R. J. M. van Hoesel ◽  
Y. C. Tong ◽  
R. D. Hollow ◽  
G. M. Clark

2015 ◽  
Vol 24 (4) ◽  
pp. 462-468 ◽  
Author(s):  
Jessica J. Messersmith ◽  
Lindsey E. Jorgensen ◽  
Jessica A. Hagg

Purpose The purpose of this study was to determine whether an alternate fitting strategy, specifically adjustment to gains in a hearing aid (HA), would improve performance in patients who experienced poorer performance in the bimodal condition when the HA was fit to traditional targets. Method This study was a retrospective chart review from a local clinic population seen during a 6-month period. Participants included 6 users of bimodal stimulation. Two performed poorer in the cochlear implant (CI) + HA condition than in the CI-only condition. One individual performed higher in the bimodal condition, but the overall performance was low. Three age range–matched users whose performance increased when the HA was used in conjunction with a CI were also included. The HA gain was reduced beyond 2000 Hz. Speech perception scores were obtained pre- and postmodification to the HA fitting. Results All listeners whose HA was programmed using the modified approach demonstrated improved speech perception scores with the modified HA fit in the bimodal condition when compared with the traditional HA fit in the bimodal condition. Conclusion Modifications to gains above 2000 Hz in the HA may improve performance for bimodal listeners who perform more poorly in the bimodal condition when the HA is fit to traditional targets.


Author(s):  
Till F. Jakob ◽  
Iva Speck ◽  
Ann-Kathrin Rauch ◽  
Frederike Hassepass ◽  
Manuel C. Ketterer ◽  
...  

Abstract Purpose The aim of the study was to compare long-term results after 1 year in patients with single-sided deafness (SSD) who were fitted with different hearing aids. The participants tested contralateral routing of signals (CROS) hearing aids and bone-anchored hearing systems (BAHS). They were also informed about the possibility of a cochlear implant (CI) and chose one of the three devices. We also investigated which factors influenced the choice of device. Methods Prospective study with 89 SSD participants who were divided into three groups by choosing BAHS, CROS, or CI. All participants received test batteries with both objective hearing tests (speech perception in noise and sound localisation) and subjective questionnaires. Results 16 participants opted for BAHS-, 13 for CROS- and 30 for CI-treatment. The greater the subjective impairment caused by SSD, the more likely patients were to opt for surgical treatment (BAHS or CI). The best results in terms of speech perception in noise (especially when sound reaches the deaf ear and noise the hearing ear), sound localization, and subjective results were achieved with CI. Conclusion The best results regarding the therapy of SSD are achieved with a CI, followed by BAHS. This was evident both in objective tests and in the subjective questionnaires. Nevertheless, an individual decision is required in each case as to which SSD therapy option is best for the patient. Above all, the patient's subjective impairment and expectations should be included in the decision-making process.


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