1,425 research outputs found
The Impact of Small Group Case-based Learning on Traditional Pharmacology Teaching
Objectives: This study aimed to measure medical students’ perceptions of incorporating small group case-based learning (CBL) in traditional pharmacology lectures. Methods: Data were collected from third-year students (N = 68; 57% males, 43% females) at Al Quds University Medical School, Palestine. The students were offered a CBL-incorporated Pharmacology-2 course after they had been taught Pharmacology-1 in the traditional format during the preceding semester. Student attitudes towards the restructured course were examined by a self-administered structured questionnaire. Results: The majority of students thought that CBL was an effective learning tool for them (82%) and that it improved their learning skills (83%), independent learning skills (74%), analytical skills (70%), and their level of preparation for exams (75%). Most students reported that team discussions addressed lecture objectives (84%). Regarding cases discussed, most responders said that the cases were appropriate to the lecture topics (96%) and that the time allocated for case discussion was sufficient (86%). A large proportion of students thought that CBL improved their communication and collaborative skills (68% and 80%, respectively) and ability to work within a team (79%). Conclusion: Pharmacology-2 course restructuring led to a significant improvement of self-reported student satisfaction, motivation, and engagement
Optimal Time Window for the Integration of Spatial Audio-Visual Information in Virtual Environments
Sound duration and location may influence both auditory and visual perception with consequences for the judgement of both auditory-visual event location and integration. This study investigated audio-visual integration in a virtual environment using both short- and long-duration auditory stimuli with visual stimuli temporally offset from the start of the auditory stimulus, to investigate the effects of top-down neural effects on perception. Two tasks were used, an auditory localization task and a detection task (judgement of audio-visual synchrony). Eleven participants took part in the study using a HTC Vive Pro. The short-duration auditory stimuli (35-ms spatialized sound) and long-duration auditory stimuli (600-ms non-spatialized sound followed by 35 ms of spatialized sound) were presented at -60°, -30°, 0°, +30° and +60° degrees azimuth, with the visual stimulus presented synchronously or asynchronously with respect to the start of the auditory stimulus. Results showed that localization errors were larger for the longer-duration stimuli and judgements of audiovisual synchrony tended to be improved for stimuli presented at ±30°. Top-down neural processing can affect spatial localization and audio-visual processing. Auditory localization errors and audio-visual synchrony detection may reveal the effects of underlying neural feedback mechanisms that can be harnessed to optimize audio-visual experiences in virtual environments
Variance of spectral entropy (VSE): an SNR estimator for speech enhancement in hearing aids
In everyday situations an individual can encounter a variety of acoustic environments. For an
individual with a hearing aid following speech in different types of background noise can often
present a challenge. For this reason, estimating the signal-to-noise ratio (SNR) is a key factor to
consider in hearing-aid design. The ability to adjust a noise reduction algorithm according to the
SNR could provide the flexibility required to improve speech intelligibility in varying levels of
background noise. However, most of the current high-accuracy SNR estimation methods are relatively
complex and may inhibit the performance of hearing aids. This study investigates the advantages
of incorporating a spectral entropy method to estimate SNR for speech enhancement in
hearing aids; in particular a variance of spectral entropy (VSE) measure. The VSE approach
avoids some of the complex computational steps of traditional statistical-model based SNR estimation
methods by only measuring the spectral entropy among frequency channels of interest
within the hearing aid. For this study, the SNR was estimated using the spectral entropy method
in different types of noise. The variance of the spectral entropy in a hearing-aid model with 10
peripheral frequency channels was used to measure the SNR. By measuring the variance of the
spectral entropy at input SNR levels between -10 dB to 20 dB, the relationship function between
the SNR and the VSE was estimated. The VSE for the speech-in-noise was measured at temporal
intervals of 1.5s. The VSE method demonstrates a more reliable performance in different types
of background noise, in particular for low-number of speakers babble noise when compared to
the US National Institute of Standards and Technology (NIST) or Waveform Amplitude Distribution
Analysis (WADA) methods. The VSE method may also reduce additional computational
steps (reducing system delays) making it more appropriate for implementation in hearing aids
where system delays should be minimized as much as possible
Causes and Architectural Solution to Heat and Nonconducive Air Condition in the Congregation Space of Worship Facilities
Passive Solar building aspire to maintain interior thermal comfort allthrough the sun’s daily and annual cycles at the same time as reducing the requirement for active cooling and heating systems. Passive solar building design is one fraction of green building design and does not consist of active systems such as mechanical ventilation or photovoltaic; on this premise of green solution lay architectural explanations and way out of the problems of heat and non conducive air condition in interior spaces irrespective of the facility type and use. This paper outlines the importance of creating and or finding green resolutions to thermal discomfort using the tool of architecture rather than machines in congregation spaces. It also reveals the demonstration/ case study of an existing worship facility experiencing severe internal thermal discomfort during worship activities, including processes required to finding solution against such challenges.Key words- Heat and Insulatio
Auditory filter-bank compression improves estimation of signal-to-noise ratio for speech in noise
Signal-to-noise ratio (SNR) estimation is necessary for many speech processing applications often challenged by nonstationary noise. The authors have previously demonstrated that the variance of spectral entropy (VSE) is a reliable estimate of SNR in nonstationary noise. Based on pre-estimated VSE-SNR relationship functions, the SNR of unseen acoustic environments can be estimated from the measured VSE. This study predicts that introducing a compressive function based on cochlear processing will increase the stability of the pre-estimated VSE-SNR relationship functions. This study demonstrates that calculating the VSE based on a nonlinear filter-bank, simulating cochlear compression, reduces the VSE-based SNR estimation errors. VSE-SNR relationship functions were estimated using speech tokens presented in babble noise comprised of different numbers of speakers. Results showed that the coefficient of determination (R2) of the estimated VSE-SNR relationship functions have absolute percentage improvements of over 26% when using a filter-bank with a compressive function, compared to when using a linear filter-bank without compression. In 2-talker babble noise, the estimation accuracy is more than 3 dB better than other published methods
Neural correlates of attention and streaming in a perceptually multistable auditory illusion
In a complex acoustic environment, acoustic cues and attention interact in the formation of streams
within the auditory scene. In this study, a variant of the “octave illusion” [Deutsch (1974). Nature
251, 307–309] was used to investigate the neural correlates of auditory streaming, and to elucidate
the effects of attention on the interaction between sequential and concurrent sound segregation in
humans. By directing subjects’ attention to different frequencies and ears, it was possible to elicit
several different illusory percepts with the identical stimulus. The first experiment tested the
hypothesis that the illusion depends on the ability of listeners to perceptually stream the target tones
from within the alternating sound sequences. In the second experiment, concurrent psychophysical
measures and electroencephalography recordings provided neural correlates of the various percepts
elicited by the multistable stimulus. The results show that the perception and neural correlates of
the auditory illusion can be manipulated robustly by attentional focus and that the illusion is constrained
in much the same way as auditory stream segregation, suggesting common underlying
mechanisms
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