ORCID Profile
0000-0002-6320-7936
Current Organisations
KU Leuven
,
Technion – Israel Institute of Technology
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Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2012
Publisher: Springer Science and Business Media LLC
Date: 12-03-2013
Publisher: Springer Science and Business Media LLC
Date: 28-07-2017
Publisher: Frontiers Media SA
Date: 15-06-2016
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2018
DOI: 10.1097/AUD.0000000000000524
Abstract: This study investigated whether age affects Flemish Digit Triplet Test (DTT) scores, as well as sensitivity and specificity of the test to detect high-frequency hearing impairment in middle age. DTT performance in broadband and low-pass filtered noise was assessed for 21 young and 61 middle-aged persons with normal-hearing sensitivity. Cutoff values based on their performance were used to evaluate sensitivity and specificity of the DTT as a screening tool in 145 middle-aged persons, with varying audiometric profiles. DTT performance for normal-hearing persons depended on age in both noise conditions. For low-pass filtered noise, the trade-off between sensitivity and specificity also increased when age-adjusted cutoff values were applied for screening in middle age. The Flemish DTT with broadband noise had high sensitivity and specificity to detect high-frequency hearing impairment in middle age. Similar results were obtained for low-pass filtered noise when cutoff values for referral were age adjusted.
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.HEARES.2016.11.004
Abstract: As people grow older, speech perception difficulties become highly prevalent, especially in noisy listening situations. Moreover, it is assumed that speech intelligibility is more affected in the event of background noises that induce a higher cognitive load, i.e., noises that result in informational versus energetic masking. There is le evidence showing that speech perception problems in aging persons are partly due to hearing impairment and partly due to age-related declines in cognition and suprathreshold auditory processing. In order to develop effective rehabilitation strategies, it is indispensable to know how these different degrading factors act upon speech perception. This implies disentangling effects of hearing impairment versus age and examining the interplay between both factors in different background noises of everyday settings. To that end, we investigated open-set sentence identification in six participant groups: a young (20-30 years), middle-aged (50-60 years), and older cohort (70-80 years), each including persons who had normal audiometric thresholds up to at least 4 kHz, on the one hand, and persons who were diagnosed with elevated audiometric thresholds, on the other hand. All participants were screened for (mild) cognitive impairment. We applied stationary and litude modulated speech-weighted noise, which are two types of energetic maskers, and unintelligible speech, which causes informational masking in addition to energetic masking. By means of these different background noises, we could look into speech perception performance in listening situations with a low and high cognitive load, respectively. Our results indicate that, even when audiometric thresholds are within normal limits up to 4 kHz, irrespective of threshold elevations at higher frequencies, and there is no indication of even mild cognitive impairment, masked speech perception declines by middle age and decreases further on to older age. The impact of hearing impairment is as detrimental for young and middle-aged as it is for older adults. When the background noise becomes cognitively more demanding, there is a larger decline in speech perception, due to age or hearing impairment. Hearing impairment seems to be the main factor underlying speech perception problems in background noises that cause energetic masking. However, in the event of informational masking, which induces a higher cognitive load, age appears to explain a significant part of the communicative impairment as well. We suggest that the degrading effect of age is mediated by deficiencies in temporal processing and central executive functions. This study may contribute to the improvement of auditory rehabilitation programs aiming to prevent aging persons from missing out on conversations, which, in turn, will improve their quality of life.
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.HEARES.2015.02.006
Abstract: Temporal cues are important for cochlear implant (CI) users when listening to speech. Users with greater sensitivity to temporal modulations show better speech recognition and modifications to stimulation parameters based on modulation sensitivity have resulted in improved speech understanding. Behavioural measures of temporal sensitivity require cooperative participants and a large amount of time. These limitations have motivated the desire for an objective measure with which to appraise temporal sensitivity for CI users. Electrically evoked auditory steady state responses (EASSRs) are neural responses to periodic electrical stimulation that have been used to predict threshold (T) levels. In this study we evaluate the use of EASSRs as a tool for assessing temporal modulation sensitivity. Modulation sensitivity was assessed behaviourally using modulation detection thresholds (MDTs) for a 20 Hz rate. On the same stimulation sites, EASSRS were measured using sinusoidally litude modulated pulse trains at 4 and 40 Hz. Measurements were taken using a bipolar configuration on 12 electrode pairs over 5 participants. Results showed that EASSR litudes and signal-to-noise ratios (SNRs) were significantly related to the MDTs. Larger EASSRs corresponded with sites of improved modulation sensitivity. This relation was driven by across-subject variation. This result indicates that EASSRs may be used as an objective measure of site-specific temporal sensitivity for CI users.
Publisher: Elsevier BV
Date: 10-2010
DOI: 10.1016/J.HEARES.2010.06.017
Abstract: Three experiments studied the effect of stimulus polarity on the Electrically Evoked Compound Action Potential (ECAP) obtained with the masker-probe paradigm on different sites along the cochlea in cochlear implant users. Experiment 1 used a biphasic cathodic-1st (BIC) masker and showed that ECAP N(1) peak latencies were longer for BIC than for biphasic anodic-1st (BIA) probes on all electrodes under test. Both the latency of each probe as well as the latency difference between BIA and BIC probes increased when the phase width (PW) of the masker and probe were increased together. Experiment 2 used maskers with long inter-phase gaps (IPGs), and, by manipulating the polarity of the second phase (closest in time to the biphasic probe), showed that only an anodic phase could mask the probe response. Experiment 3 used maskers and probes with long IPGs and measured ECAPs to the first phase of the probe ECAPs could be measured when both this phase and the second phase of the masker were anodic, but not when they were cathodic. Our results extend those of a previous study, showing that the auditory nerve in humans is preferentially activated by anodic stimulation, to different sites along the cochlea.
Publisher: Elsevier BV
Date: 08-2012
DOI: 10.1016/J.HEARES.2012.05.003
Abstract: In cochlear implants (CI) bipolar (BP) electrical stimulation has been suggested as a method to reduce the spread of current along the cochlea. However, behavioral measurements in BP mode have shown either similar or worse performance than in monopolar (MP) mode. This could be explained by a bimodal excitation pattern, with two main excitation peaks at the sites of the stimulating electrodes. We measured the spread of excitation (SOE) by means of the electrically evoked compound action potential (ECAP), obtained using the forward-masked paradigm. The aim was to measure the bimodality of the excitation and to determine whether it could be reduced by using asymmetric pulses. Three types of maskers shapes were used: symmetric (SYM), pseudomonophasic (PS), and symmetric with a long inter-phase gap (SYM-IPG) pulses. Maskers were presented in BP + 9 (wide), BP + 3 (narrow) and MP (only SYM) mode on fixed electrodes. The SOE obtained with the MP masker showed a main excitation peak close to the masker electrode. Wide SYM maskers produced bimodal excitation patterns showing two peaks close to the electrodes of the masker channel, whereas SYM-IPG maskers showed a single main peak near the electrode for which the masker's second phase (responsible for most of the masking) was anodic. Narrow SYM maskers showed complex and wider excitation patterns than asymmetric stimuli consistent with the overlap of the patterns produced by each channel's electrodes. The masking produced by narrow SYM-IPG and PS stimuli was more pronounced close to the masker electrode for which the effective phase was anodic. These results showed that the anodic polarity is the most effective one in BP mode and that the bimodal patterns produced by SYM maskers could be partially reduced by using asymmetric pulses.
Publisher: Informa UK Limited
Date: 24-06-2016
DOI: 10.1080/13825585.2016.1200005
Abstract: The main objective of this study is to investigate memory task performance in different age groups, irrespective of hearing status. Data are collected on a short-term memory task (WAIS-III Digit Span forward) and two working memory tasks (WAIS-III Digit Span backward and the Reading Span Test). The tasks are administered to young (20-30 years, n = 56), middle-aged (50-60 years, n = 47), and older participants (70-80 years, n = 16) with normal hearing thresholds. All participants have passed a cognitive screening task (Montreal Cognitive Assessment (MoCA)). Young participants perform significantly better than middle-aged participants, while middle-aged and older participants perform similarly on the three memory tasks. Our data show that older clinically normal hearing persons perform equally well on the memory tasks as middle-aged persons. However, even under optimal conditions of preserved sensory processing, changes in memory performance occur. Based on our data, these changes set in before middle age.
Publisher: F1000 Research Ltd
Date: 16-05-2018
DOI: 10.12688/WELLCOMEOPENRES.12594.2
Abstract: Background : Countries in Southeast Asia are working to eliminate multidrug-resistant falciparum malaria, a major cause of mortality in tropical regions. Malaria is declining but transmission persists in many rural areas and among forest workers and isolated populations. In these remote communities, conventional health services and education are limited. Mobilising and educating these populations require new approaches as many people are illiterate and do not attend village meetings. This article describes a qualitative study to assess the feasibility of a drama project as a community engagement strategy. Methods : A drama project was conducted in twenty villages in Cambodia with three key messages: to use insecticide-treated bednets and repellents, to get early diagnosis and treatment, and to learn about risks of forest-acquired malaria. Qualitative interviews were conducted with the drama team members, village malaria workers, local health staffs and villagers, to explore the feasibility of using drama to engage the community and the associated challenges. Results : 29 people were interviewed, which included 18 semi-structured interviews and one focus group discussion. Analysis of the interviews resulted in development of the following seven themes: i) exposure to malaria and engagement activities, ii) readiness and barriers to participation, iii) understanding and learning about malaria using drama, iv) entertainment value and engagement method preferences, v) challenges to community engagement, vi) future participation and vii) sustainability. The event saw a very positive response, with an encouraging average participation rate of 66%. The project faced several challenges including logistic problems, rescheduling due to raining season, and time- and budget-constraints. Conclusions : Our evaluation demonstrated that the drama project was feasible in promoting awareness and understanding of malaria prevention and control. Audience members perceived drama as entertaining and as the preferred choice of engagement activity. Participatory drama could be considered as part of the community engagement for malaria elimination.
Publisher: Wiley
Date: 23-12-2008
DOI: 10.1111/J.1539-6924.2008.01130.X
Abstract: We focus on a class of multicriteria methods that are commonly used in environmental decision making--those that employ the weighted linear average algorithm (and this includes the popular analytic hierarchy process (AHP)). While we do not doubt the potential benefits of using formal decision methods of this type, we draw attention to the consequences of not using them well. In particular, we highlight a property of these methods that should not be overlooked when they are applied in environmental and wider decision-making contexts: the final decision or ranking of options is dependent on the choice of performance scoring scales for the criteria when the criteria weights are held constant. We compare this "sensitivity" to a well-known criticism of the AHP, and we go on to describe the more general lesson when it comes to using weighted linear average methods--a lesson concerning the relationship between criteria weights and performance scoring scales.
Publisher: Wiley
Date: 25-03-2012
DOI: 10.1002/HBM.22052
No related grants have been discovered for Astrid van Wieringen.