493 research outputs found
Level discrimination of speech sounds by hearing-impaired individuals with and without hearing amplification
Objectives: The current study was designed to see how hearing-impaired individuals judge level differences between speech sounds with and without hearing amplification. It was hypothesized that hearing aid compression should adversely affect the user's ability to judge level differences.
Design: Thirty-eight hearing-impaired participants performed an adaptive tracking procedure to determine their level-discrimination thresholds for different word and sentence tokens, as well as speech-spectrum noise, with and without their hearing aids. Eight normal-hearing participants performed the same task for comparison.
Results: Level discrimination for different word and sentence tokens was more difficult than the discrimination of stationary noises. Word level discrimination was significantly more difficult than sentence level discrimination. There were no significant differences, however, between mean performance with and without hearing aids and no correlations between performance and various hearing aid measurements.
Conclusions: There is a clear difficulty in judging the level differences between words or sentences relative to differences between broadband noises, but this difficulty was found for both hearing-impaired and normal-hearing individuals and had no relation to hearing aid compression measures. The lack of a clear adverse effect of hearing aid compression on level discrimination is suggested to be due to the low effective compression ratios of currently fit hearing aids
B_s decays at Belle
We report recent results obtained with the Belle detector using a 23.6
fb^{-1} data sample collected on the Y(5S) resonance at the KEKB asymmetric
energy e^+ e^- collider. Inclusive semileptonic B_s^0 -> X^+ l^- \nu decays are
studied for the first time and the branching fraction is measured. Combining
the electron and muon channels, we obtain Bf(B_s^0 -> X^+ l^- \nu) = (10.2 \pm
0.8 \pm 0.9)%. Also, the radiative penguin decay B_s^0 -> \phi \gamma is
observed for the first time, and an improved upper limit for the decay B_s^0
\to \gamma \gamma is obtained.Comment: Proceedings of the EPS/HEP 2007 Conference, Manchester, England, July
2007 (on behalf of the Belle collaboration), 3 pages, 2 figure
The Sensitivity of Hearing-Impaired Adults to Acoustic Attributes in Simulated Rooms
In previous studies we have shown that older hearing-impaired individuals are relatively insensitive to changes in the apparent width of broadband noises when those width changes were based on differences in interaural coherence [W. Whitmer, B. Seeber and M. Akeroyd, J. Acoust. Soc. Am. 132, 369-379 (2012)]. This insensitivity has been linked to senescent difficulties in resolving binaural fine-structure differences. It is therefore possible that interaural coherence, despite its widespread use, may not be the best acoustic surrogate of spatial perception for the aged and impaired. To test this, we simulated the room impulse responses for various acoustic scenarios with differing coherence and lateral (energy) fraction attributes using room modelling software (ODEON). Bilaterally impaired adult participants were asked to sketch the perceived size of speech tokens and musical excerpts that were convolved with these impulse responses and presented to them in a sound-dampened enclosure through a 24-loudspeaker array. Participants' binaural acuity was also measured using an interaural phase discrimination task. Corroborating our previous findings, the results showed less sensitivity to interaural coherence in the auditory source width judgments of older hearing-impaired individuals, indicating that alternate acoustic measurements in the design of spaces for the elderly may be necessary
Recording and Analysis of Head Movements, Interaural Level and Time Differences in Rooms and Real-World Listening Scenarios
The science of how we use interaural differences to localise sounds has been studied for over a century and in many ways is well understood. But in many of these psychophysical experiments listeners are required to keep their head still, as head movements cause changes in interaural level and time differences (ILD and ITD respectively). But a fixed head is unrealistic. Here we report an analysis of the actual ILDs and ITDs that occur as people naturally move and relate them to gyroscope measurements of the actual motion. We used recordings of binaural signals in a number of rooms and listening scenarios (home, office, busy street etc). The listener's head movements were also recorded in synchrony with the audio, using a micro-electromechanical gyroscope. We calculated the instantaneous ILD and ITDs and analysed them over time and frequency, comparing them with measurements of head movements. The results showed that instantaneous ITDs were widely distributed across time and frequency in some multi-source environments while ILDs were less widely distributed. The type of listening environment affected head motion. These findings suggest a complex interaction between interaural cues, egocentric head movement and the identification of sound sources in real-world listening situations
Physics at SuperB
Flavour will play a crucial role in understanding physics beyond the Standard
Model. Progress in developing a future programme to investigate this central
area of particle physics has recently passed a milestone, with the completion
of the conceptual design report for SuperB, a very high luminosity, asymmetric
e+e- collider. This article summarizes the important role of SuperB in
understanding new physics in the LHC era.Comment: 4 pages, 2 figures. To appear in the proceedings of the International
Europhysics Conference on High Energy Physics (EPS-HEP2007), Manchester,
England, 19-25 July 200
A comprehensive survey of hearing questionnaires: how many are there, what do they measure, and how have they been validated?
The self-report questionnaire is a popular tool for measuring outcomes in trials of interventions for hearing impairment. Many have been designed over the last fifty years, and there is no single standard questionnaire that is widely accepted and used. We felt it would be a valuable resource to have a comprehensive collection of all adult hearing-loss questionnaires (excluding those wholly devoted to tinnitus, children, or cochlear implants) and to survey their degree of validation. We collated copies of every published hearing difficulty questionnaire that we could find. The search was primarily done by iterative reference searching. Questionnaire topics were obtained by mapping the text of each questionnaire onto a set of categories; reports of validation methods were taken from the primary paper(s) on each questionnaire. In total we found 139 hearing-specific questionnaires (though many others were found that were primarily about something else). Though not formally systematic, we believe that we have included every questionnaire that is important, most of those of some notice, and a fair fraction of those obscure. We classified 111 as “primary” and the remaining 28 as “contractions”, being shortened versions of a primary without any new questions. In total, there were 3618 items across all the primary questionnaires. The median number of items per questionnaire was 20; the maximum was 158. Across all items, about one third were concerned with the person’s own hearing, another third with the repercussions of it, and about a quarter with hearing aids. There was a wide range in validation methods, from only using items chosen statistically from wider pools and with formal validation against independent measures of clinical outcomes, to just reporting a correlation with an audiogram measure of hearing loss. The “state of play” of the field of hearing questionnaires will be discussed
Charged Higgs bosons in the Next-to MSSM (NMSSM)
The charged Higgs boson decays and
are studied in the framework of the next-to Minimal Supersymmetric Standard
Model (NMSSM). It is found that the decay rate for can
exceed the rates for the and channels both below and above
the top-bottom threshold. The dominance of is most readily
achieved when has a large doublet component and small mass. We also study
the production process at the LHC followed by the decay
which leads to the signature . We suggest
that is a promising discovery channel for a light charged
Higgs boson in the NMSSM with small or moderate and dominant decay
mode . This signature can also arise from
the Higgsstrahlung process followed by the decay . It is shown that there exist regions of parameter space where these
processes can have comparable cross sections and we suggest that their
respective signals can be distinguished at the LHC by using appropriate
reconstruction methods.Comment: 20 pages, 22 eps figures, more reference adde
Carbohydrate mouth rinse improves resistance exercise capacity in the glycogen-lowered state
The effect of carbohydrate mouth rinse (CHO MR) on resistance exercise performance is equivocal, and may be moderated by carbohydrate availability. This study determined the effect of CHO MR on low-load resistance exercise capacity completed in a fed but glycogen-lowered state. Twelve resistance-trained men (age: 22±4 years; height: 1.79±0.05m; weight: 78.7±7.8kg; bench press 1-RM: 87±21kg; squat 1-RM: 123±19kg) completed two fed-state resistance exercise bouts consisting of 6 sets of bench press and 6 sets of squat to failure at 40% 1-RM. Each bout was preceded by glycogen-depleting cycling the evening before, with feeding controlled to create acute energy deficit and maintain low muscle glycogen. During resistance exercise, participants rinsed with either a 6% CHO MR solution or a taste-matched placebo (PLA) between sets. Total volume workload was greater with CHO MR (9354±2051kg vs. 8525±1911kg, p=0.010). Total number of repetitions of squat were greater with CHO MR (107±26 vs. 92±16, p=0.017); the number of repetitions of bench press were not significantly different (CHO MR: 120±24 vs. PLA: 115±22, p=0.146). This was independent of differences in feeling or arousal. CHO MR may be an effective ergogenic aid for athletes completing resistance exercise when in energy deficit and with low carbohydrate availability. Novelty • CHO MR can increase low-load resistance exercise capacity undertaken in a glycogen-lowered but fed state. • This effect was driven by a greater number of repetitions-to-failure in the squat – using muscles lowered in glycogen content with exhaustive cycling on the evening prior to resistance exercise – but not bench press
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