Evaluating Use of the Doppler Effect to Enhance Auditory Alerts

This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Human–Computer Interaction on 10/02/2021, available online: https://doi.org/10.1080/10447318.2020.1870818Auditory alerts are an essential part of many multi-modal interaction scenarios, particularly in safety and mission critical settings, such as hospitals and transportation. A variety of strategies can be employed in the design of auditory alerts, often orienting manipulation of volume and pitch parameters. However, manipulations by applying a Doppler effect are under-investigated. A perceptual listening test is conducted (n = 100) using multiple alert sounds that are subjected to a variety of volume, pitch, and Doppler manipulations, with the unaltered sounds serving as a benchmark. Applying a mixed methods approach consisting of inferential statistics and thematic analysis, it is found that decreases in volume and a Doppler simulation of a sound moving away reduce importance and urgency, increase safety, are harder to detect, and are perceived as being more distant in perceptions of auditory alerts. Further, increases in volume and a Doppler simulation of a sound approaching are effective in communicating safety, whilst pitch manipulations were much less effective. Further work is required to provide wider, ecologically valid, verification of these findings, particularly as to how listener detection of Doppler and volume manipulations can be improved

Variations in running technique between female sprinters, middle, and distance runners

International Journal of Exercise Science 6(1) : 43-51, 2013. In the sport of track and field, runners excel not only due to physiological characteristics but also aspects in running technique. Optimal technique allows runners the perfect the balance between running speed and economy. The ideal movement pattern may vary between events as the goal goes from economy of movement in the long-distance events to speed and power in the sprints. Understanding how each type of runner moves differently will help coaches more effectively train their athletes for each specific running event. This study was conducted to determine if sprinters, middle-distance, and long-distance runners would exhibit differences in form while running at the same speeds. Thirty female Division I collegiate runners participated in this study. Runners were separated into categories based on the events for which they were currently training in: 10 sprinters, 10 middle-distance, and 10 long-distance runners. Participants were asked to run twenty-two steps at five selected speeds. Knee angles, ground contact time, center of mass separation, and stride length were measured using a Vicon Nexus motion analysis system. Data was processed using analysis of variance and a Tukey post hoc analysis. Significant differences (p \u3c .05) occurred between long-distance runners and the other two groups (middle-distance and sprinters) for knee range, ground contact time, center of mass separation, and stride length at all five speeds. While running at the same speeds, there are specific characteristics of technique that distinguish long-distance runners from middle-distance and sprinters

Subjective Evaluation of Music Compressed with the ACER Codec Compared to AAC, MP3, and Uncompressed PCM

Audio data compression has revolutionised the way in which the music industry and musicians sell and distribute their products. Our previous research presented a novel codec named ACER (Audio Compression Exploiting Repetition), which achieves data reduction by exploiting irrelevancy and redundancy in musical structure whilst generally maintaining acceptable levels of noise and distortion in objective evaluations. However, previous work did not evaluate ACER using subjective listening tests, leaving a gap to demonstrate its applicability under human audio perception tests. In this paper, we present a double-blind listening test that was conducted with a range of listeners (N=100). The aim was to determine the efficacy of the ACER codec, in terms of perceptible noise and spatial distortion artefacts, against de facto standards for audio data compression and an uncompressed reference. Results show that participants reported no perceived differences between the uncompressed, MP3, AAC, ACER high quality, and ACER medium quality compressed audio in terms of noise and distortions but that the ACER low quality format was perceived as being of lower quality. However, in terms of participants’ perceptions of the stereo field, all formats under test performed as well as each other, with no statistically significant differences. A qualitative, thematic analysis of listeners’ feedback revealed that the noise artefacts that produced the ACER technique are different from those of comparator codecs, reflecting its novel approach. Results show that the quality of contemporary audio compression systems has reached a stage where their performance is perceived to be as good as uncompressed audio. The ACER format is able to compete as an alternative, with results showing a preference for the ACER medium quality versions over WAV, MP3, and AAC. The ACER process itself is viable on its own or in conjunction with techniques such as MP3 and AAC

Evaluating Use of the Doppler Effect to Enhance Auditory Alerts

Auditory alerts are an essential part of many multi-modal interaction scenarios, particularly in safety and mission critical settings, such as hospitals and transportation. A variety of strategies can be employed in the design of auditory alerts, often orienting manipulation of volume and pitch parameters. However, manipulations by applying a Doppler effect are under-investigated. A perceptual listening test is conducted (n = 100) using multiple alert sounds that are subjected to a variety of volume, pitch, and Doppler manipulations, with the unaltered sounds serving as a benchmark. Applying a mixed methods approach consisting of inferential statistics and thematic analysis, it is found that decreases in volume and a Doppler simulation of a sound moving away reduce importance and urgency, increase safety, are harder to detect, and are perceived as being more distant in perceptions of auditory alerts. Further, increases in volume and a Doppler simulation of a sound approaching are effective in communicating safety, whilst pitch manipulations were much less effective. Further work is required to provide wider, ecologically valid, verification of these findings, particularly as to how listener detection of Doppler and volume manipulations can be improved

Anomalous optical surface absorption in nominally pure silicon samples at 1550 nm

The announcement of the direct detection of Gravitational Waves (GW) by the LIGO and Virgo collaboration in February 2016 has removed any uncertainty around the possibility of GW astronomy. It has demonstrated that future detectors with sensitivities ten times greater than the Advanced LIGO detectors would see thousands of events per year. Many proposals for such future interferometric GW detectors assume the use of silicon test masses. Silicon has low mechanical loss at low temperatures, which leads to low displacement noise for a suspended interferometer mirror. In addition to the low mechanical loss, it is a requirement that the test masses have a low optical loss. Measurements at 1550 nm have indicated that material with a low enough bulk absorption is available; however there have been suggestions that this low absorption material has a surface absorption of > 100 ppm which could preclude its use in future cryogenic detectors. We show in this paper that this surface loss is not intrinsic but is likely to be a result of particular polishing techniques and can be removed or avoided by the correct polishing procedure. This is an important step towards high gravitational wave detection rates in silicon based instruments

The first year Physics online diary project

This article considers the laboratory learning experiences of first-year physics students at The University of New South Wales (UNSW). The data was gathered by online student diaries, with a range of questions completed at weekly intervals over three semesters, plus focus groups. Data from large scale surveys of students was used to supplement and provide context for the data provided by the group of diary keepers. The textual data from the diaries was analysed using NVIVO. Based on the data collected the existing laboratory courses were modified using an action research approach over three semesters

Differences in fungal immune recognition by monocytes and macrophages : N-mannan can be a shield or activator of immune recognition

Acknowledgements We thank Professor Gordon Brown for Fc-dectin-1 and Professor David Williams for glucan phosphate. We also thank Kevin MacKenzie, Debbie Wilkinson, Gillian Milne, and Lucy Wright at the University of Aberdeen Core Microscopy & Histology Facility.Peer reviewedPublisher PD

Low-temperature mechanical dissipation of thermally evaporated indium film for use in interferometric gravitational wave detectors

Indium bonding is under consideration for use in the construction of cryogenic mirror suspensions in future gravitational wave detectors. This paper presents measurements of the mechanical loss of a thermally evaporated indium film over a broad range of frequencies and temperatures. It provides an estimate of the resulting thermal noise at 20 K for a typical test mass geometry for a cryogenic interferometric gravitational wave detector from an indium layer between suspension elements

Yeast species-specific, differential inhibition of β-1,3-glucan synthesis by poacic acid and caspofungin

We sincerely thank Jeff Piotrowski and John Ralph for providing poacic acid, and David Perlin for providing C. glabrata fks1Δ and fks2Δ mutant strains and clinical isolates (DPL series) for this study. We thank Carol Munro, Sam Miller and Louise Walker for helpful discussions; and Raif Yuecel, Attila Bebes, and Linda Duncan in the Iain Fraser Cytometry Centre (IFCC) for FACS, and Kevin MacKenzie, Debbie Wilkinson, Gillian Milne, and Lucy Wright for microscopy at the University of Aberdeen core facilities. This work was supported by the Wellcome Trust (101873, 086827, 075470, & 200208) and MRC Centre for Medical Mycology (N006364/1), and Grants-in-Aid for Scientific Research from the Ministry of Education Culture, Sports, Science and Technology, Japan (24370002 and 15H04402 to Y.O.).Peer reviewedPublisher PD

Returning a lost process by reintroducing a locally extinct digging marsupial

The eastern bettong (Bettongia gaimardi), a medium-sized digging marsupial, was reintroduced to a predator-free reserve after 100 years of absence from the Australian mainland. The bettong may have the potential to restore temperate woodlands degraded by a history of livestock grazing, by creating numerous small disturbances by digging. We investigated the digging capacity of the bettong and compared this to extant fauna, to answer the first key question of whether this species could be considered an ecosystem engineer, and ultimately if it has the capacity to restore lost ecological processes. We found that eastern bettongs were frequent diggers and, at a density of 0.3–0.4 animals ha−1, accounted for over half the total foraging pits observed (55%), with echidnas (Tachyglossus aculeatus), birds and feral rabbits (Oryctolagus cuniculus) accounting for the rest. We estimated that the population of bettongs present dug 985 kg of soil per ha per year in our study area. Bettongs dug more where available phosphorus was higher, where there was greater basal area of Acacia spp. and where kangaroo grazing was less. There was no effect on digging of eucalypt stem density or volume of logs on the ground. While bettong digging activity was more frequent under trees, digging also occurred in open grassland, and bettongs were the only species observed to dig in scalds (areas where topsoil has eroded to the B Horizon). These results highlight the potential for bettongs to enhance soil processes in a way not demonstrated by the existing fauna (native birds and echidna), and introduced rabbit