Traditionally, the place-pitch 'tonotopically' organized auditory neural pathway was considered to be hard-wired. Cochlear implants restore hearing by arbitrarily mapping frequency-amplitude information. This study shows that recipients, after a long period of sound deprivation, preserve a level of auditory plasticity, enabling them to swiftly and concurrently learn speech understanding with two alternating, distinct frequency maps.
View Article and Find Full Text PDFBackground: Due to variation in electrode design, insertion depth and cochlear morphology, patients with a cochlear implant (CI) often have to adapt to a substantial mismatch between the characteristic response frequencies of cochlear neurons and the stimulus frequencies assigned to electrode contacts. We introduce an imaging-based fitting intervention, which aimed to reduce frequency-to-place mismatch by aligning frequency mapping with the tonotopic position of electrodes. Results were evaluated in a novel trial set-up where subjects crossed over between intervention and control using a daily within-patient randomized approach, immediately from the start of CI rehabilitation.
View Article and Find Full Text PDFIntroduction: Estimating differences in neural health across different sites within the individual cochlea potentially enables clinical applications for subjects with a cochlear implant. The electrically evoked compound action potential (ECAP) is a measure of neural excitability that possibly provides an indication of a neural condition. There are many factors, however, that affect this measure and increase the uncertainty of its interpretation.
View Article and Find Full Text PDFObjectives: Early-deafened, late-implanted adolescents and adults constitute a unique group of cochlear implant (CI) users, showing a large variability in outcomes. The current systematic review aimed to determine which preimplantation factors are relevant in predicting postoperative outcomes in this patient group.
Design: A systematic search for studies published between 2000 and September 2017 was performed in five electronic databases (PubMed, Embase, the Cochrane library, CINAHL, and PsycInfo).
Objectives: Cochlear implantation in early-deafened patients, implanted as adolescents or adults, is not always advised due to poor expected outcomes. In order to judge whether such reluctance is justified, the current systematic review aimed to gather all available evidence on postoperative outcomes obtained by early-deafened patients using a state-of-the art cochlear implant (CI).
Design: Five electronic databases (PubMed, Embase, the Cochrane library, CINAHL, and PsycInfo) were systematically searched for studies in English, French, German, or Dutch, published between 2000 and September 2017.
Objectives: It is known that early-deafened cochlear implant (CI) users are a very heterogeneously performing group. To gain more insight into this population, this study investigated (1) postoperative changes in auditory performance over time based on various outcome measures, focusing on poor performers, (2) self-perceived outcomes, (3) relations between auditory and self-perceived outcomes, and (4) preimplantation factors predicting postoperative outcomes.
Methods: Outcomes were assessed prospectively in a group of 27 early-deafened, late-implanted CI users, up to 3 years after implantation.
Objective: This study investigated the hypotheses that (1) prelingually deafened CI users do not have perfect electrode discrimination ability and (2) the deactivation of non-discriminable electrodes can improve auditory performance.
Design: Electrode discrimination difference limens were determined for all electrodes of the array. The subjects' basic map was subsequently compared to an experimental map, which contained only discriminable electrodes, with respect to speech understanding in quiet and in noise, listening effort, spectral ripple discrimination and subjective appreciation.
Objectives: Many late-implanted prelingually deafened cochlear implant (CI) patients struggle to obtain open-set speech understanding. Because it is known that low-frequency temporal-envelope information contains important cues for speech understanding, the goal of this study was to compare the temporal-envelope processing abilities of late-implanted prelingually and postlingually deafened CI users. Furthermore, the possible relation between temporal processing abilities and speech recognition performances was investigated.
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