Psychoacoustic investigation of auditory cues involved in human underwater sound localization

International audienceTheoretical arguments about underwater sound localization predict that auditory cuesused in air are impaired in water. However, long term acclimatization could emerge due toexposure to the environment. We have compared localization abilities of expert and novicedivers. The localization task was conducted for 8 azimuthal sound positions and 8 signals(0.4, 1, 2, 4, 6, 8, 10 kHz, white-noise). Results indicate that localization was better forexperts: they made more correct localizations and their directional response distribution wasless dispersed. These results demonstrate long term acclimatization in the processing oflocalization cues under water, particularly of interaural cues

Protecting and promoting the health and safety of older workers: opportunities and challenges

As the 21st century proceeds, individuals are increasingly working into later years to support themselves and maintain their quality of life. This changing pattern of employment has implications for workers, employers and society alike. Although older workers have much to contribute, individuals may experience health issues or physical, sensory or psychological changes related to ageing. Health and safety statistics indicate that older workers are a vulnerable group. Employers then, have a responsibility to examine the working environment and protect those with reduced capabilities. For society to function, older workers need to be able to remain in work, otherwise this will impact on both the economy and older individuals quality of life. This thesis aimed to understand the opportunities and challenges employers encounter when trying to protect and promote the health and safety of older workers. The research used qualitative approaches, combining interviews and focus groups to provide rich data on the circumstances of older workers. Triangulation was used, collecting data over different time periods, from different sources, to help balance out any weaknesses across the studies. Data were analysed using thematic analysis. A review of the literature found that there is no consistent definition of ageing or older worker. Many researchers have used chronological age and, therefore, this thesis used 50 as a threshold. The literature highlights that older workers have a wealth of knowledge and skills to bring to the workplace. Negative perceptions, however, regarding natural ageing and adaptability exist. Other authors have argued that organisations need to provide a safe environment for older workers and implement measures to mitigate changes in abilities, whilst recognising that there is no one size fits all strategy. First, an initial scoping study was undertaken with employers, which sought to understand their perceptions concerning the ageing workforce. The study also collected information on the health and safety age management strategies that have been implemented within the organisations. Interviews with employers (senior managers who influence health and safety management strategies) (n=41) revealed that, in line with literature, there is recognition that older workers bring benefits to the workplace. However, some comments demonstrated inaccurate stereotyping. The interviews found that these employers were uncertain how to proceed with implementing actions to protect the health and safety of their older workers. Two subsequent studies, consisting of focus groups (n=10) and interviews (n=50) were then conducted, which explored older workers experiences of working into later life and their views on the issues identified by the employer interview study. The older worker interviews also examined their perceptions regarding their health and capabilities, appropriate health and safety measures in response to this and interviewees anticipated future in the workforce. Older workers explained that they do not feel supported or engaged. They are fearful of reporting capability changes that may affect their ability to perform work tasks, as they believe this may have negative consequences for their future employment. During discussions, they suggested various measures that may help them remain in the workforce for longer. The information gathered during the literature review and the findings from the first three studies, were then used to develop examples of good practice health and safety measures that organisations could implement to help protect and promote the health and safety of older workers. A final interview study with key employer representatives (n=16) was conducted, to understand whether the health and safety good practice measures might be considered beneficial and achievable. This study found that although organisations recognised the benefits of health and safety measures tailored for older workers, the feasibility of some of the suggestions was in doubt. Budgetary constraints, insufficient time and lack of necessary knowledge were seen as particular obstacles to implementation. This thesis has identified that although research evidence exists in relation to measures to support the health and safety of older workers, e.g. the benefits of health promotion, improved work scheduling, workplace assessments etc, this is rarely translated into practice. Within organisations, there is uncertainty about age management for older workers and limited understanding of the divergent needs as workers capabilities change. The default position then becomes to cater for a typical worker. A coordinated multi-disciplinary approach between health and safety, occupational health, human resources and operational management is required. This thesis argues for an integrated age management strategy, with an emphasis on proactive prevention, in the interests of protecting and promoting the health and safety of older workers

Making Scholarly Profiles Work

A presentation on scholarly profiles given at the 2016 January Symposium at James Madison University

Investigation of auditory cues involved in human underwater sound localization

International audienceTheoretical arguments about underwater sound localization predict that auditory cues used in air areimpaired in water, resulting in a theoretical inability to locate sounds under water. An azimuth identification task wasconducted under water for 8 positions (0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°) and 3 signals (400 Hz sine, 6 kHzsine, white-noise). Results demonstrate that localization was possible, at least for lateral positions, indicating thatinteraural cues are processed. The absence of spectral pinna cues may explain a large front/back confusion pattern

Facilitators and barriers to the protection and promotion of the health and safety of older workers

© 2017 Institution of Occupational Safety and Health. Individuals may experience health issues or physical, sensory or psychological capability changes related to ageing. With the removal of the default retirement age in the UK, older workers can remain in work well into later life. Health and safety statistics, however, indicate that they are a vulnerable group. Older workers have much to contribute, but employers have a responsibility to examine the working environment to protect those with reduced capabilities. This article reviews two qualitative studies examining the facilitators and barriers to implementing age management strategies to promote the health and safety of older workers. The findings reveal that employers are uncertain how to proceed with implementing actions to protect older workers. Discussions with older workers reveal they do not feel supported or engaged. They are fearful of reporting any capability changes that may affect their ability to perform work tasks as they believe this may have negative consequences for their future employment. A co-ordinated multi-disciplinary approach between human resources, operational management, health and safety specialists and occupational health functions is required

Management strategies to help engage, protect and promote the health and safety of older workers

Management strategies to help engage, protect and promote the health and safety of older worker

Costs of occupational ill‐health in construction

Costs of occupational ill‐health in constructio

Focalisation on the temporal context of complex sequences

Proceedings of the 9th International Conference on Auditory Display (ICAD), Boston, MA, July 7-9, 2003.Studies of the perception of sound sequences indicate the existence of an optimal processing rate [1]: sequences in which sound events occur at rates within this range are processed in more depth than events within faster or slower sequences. But what happens if two sequences occur simultaneously at different rates? We investigate whether or not listeners focus preferentially on (and process in more depth) the sequence which is closest to their optimal rate. We do this by measuring the way listeners hear and synchronise with complex sequences composed of two co-occurring subsequences. In a withinsubjects design, participants completed four tasks, two perceptual and two motor. The results indicate in particular that: 1) irregularity detection was better within the sequences closest to each participant's optimal rate, 2) participants tended to synchronise with the same subsequence, and 3) a strong link between the optimal tempi was observed in all four tasks

A Combined Solar Electric and Storable Chemical Propulsion Vehicle for Piloted Mars Missions

The Mars Design Reference Architecture (DRA) 5.0 explored a piloted Mars mission in the 2030 timeframe, focusing on architecture and technology choices. The DRA 5.0 focused on nuclear thermal and cryogenic chemical propulsion system options for the mission. Follow-on work explored both nuclear and solar electric options. One enticing option that was found in a NASA Collaborative Modeling for Parametric Assessment of Space Systems (COMPASS) design study used a combination of a 1-MW-class solar electric propulsion (SEP) system combined with storable chemical systems derived from the planned Orion crew vehicle. It was found that by using each propulsion system at the appropriate phase of the mission, the entire SEP stage and habitat could be placed into orbit with just two planned Space Launch System (SLS) heavy lift launch vehicles assuming the crew would meet up at the Earth-Moon (E-M) L2 point on a separate heavy-lift launch. These appropriate phases use high-thrust chemical propulsion only in gravity wells when the vehicle is piloted and solar electric propulsion for every other phase. Thus the SEP system performs the spiral of the unmanned vehicle from low Earth orbit (LEO) to E-M L2 where the vehicle meets up with the multi-purpose crew vehicle. From here SEP is used to place the vehicle on a trajectory to Mars. With SEP providing a large portion of the required capture and departure changes in velocity (delta V) at Mars, the delta V provided by the chemical propulsion is reduced by a factor of five from what would be needed with chemical propulsion alone at Mars. This trajectory also allows the SEP and habitat vehicle to arrive in the highly elliptic 1-sol parking orbit compatible with envisioned Mars landing concepts. This paper explores mission options using between SEP and chemical propulsion, the design of the SEP system including the solar array and electric propulsion systems, and packaging in the SLS shroud. Design trades of stay time, power level, specific impulse and propellant type are discussed