Response to "comment on 'reducing seat dip attenuation'" J. Acoust. Soc. Am. 110, 1260 (2001)

This letter responds to Klepper's comments [J. Acoust. Soc. Am. 110, 1260 (2001)] on the subject paper, which is concerned with ameliorating seat dip attenuation in auditoria by introducing a pit under the seats. Klepper asks what the effect of the pit will be on seat absorption and reverberation times. A little evidence is presented to support the idea that low-frequency absorption in an auditorium will increase with a pit. It is further speculated that reverberation times could be predicted by using a coupled space model. Klepper's suggestion of an experiment to answer his questions is supported. (C) 2001 Acoustical Society of America

Reducing seat dip attenuation

Strategies fur reducing seat dip attenuation in concert halls are considered. It is shown that the dip is established 4 ms after the direct sound from the stage arrives at the listener. Sound scattered from the seats and floor is the main cause of the dip. By controlling these very early reflections the attenuation can be reduced to below its subjective threshold. With this in mind, changes to the shape and impedance of the seats and floor are trialed using a boundary element model and a physical scale model. It is found that the seat dip effect can be rendered inaudible by introducing a l-m pit under the seats. Smaller improvements are produced by changing the impedance of the seat squab. (C) 2000 Acoustical Society of America

Why artificial light at night should be a focus for global change research in the 21st century

The environmental impacts of artificial light at night have been a rapidly growing field of global change science in recent years. Yet, light pollution has not achieved parity with other global change phenomena in the level of concern and interest it receives from the scientific community, government and nongovernmental organizations. This is despite the globally widespread, expanding and changing nature of night-time lighting and the immediacy, severity and phylogenetic breath of its impacts. In this opinion piece, we evidence 10 reasons why artificial light at night should be a focus for global change research in the 21st century. Our reasons extend beyond those concerned principally with the environment, to also include impacts on human health, culture and biodiversity conservation more generally. We conclude that the growing use of night-time lighting will continue to raise numerous ecological, human health and cultural issues, but that opportunities exist to mitigate its impacts by combining novel technologies with sound scientific evidence. The potential gains from appropriate management extend far beyond those for the environment, indeed it may play a key role in transitioning towards a more sustainable society

Influence of visual stimuli on perceptual attributes of spatial audio

Reproduced audio is often accompanied with visuals (i.e. television, virtual reality, gaming, and cinema). However, the audio technology for these systems is often researched and evaluated in isolation from the visual component. Previous research indicates that the auditory and visual modalities are not processed separately. For example, visual stimuli can influence ratings of audio quality and vice versa. This paper presents an experiment to investigate the influence of visual stimuli on a set of attributes relevant to the perception of spatial audio. Eighteen participants took part in a paired comparison listening test where they were asked to judge pairs of stimuli rendered to fourteen-, five-, and two-channel systems using ten perceptual attributes. The stimuli were presented in audio only and audio-visual conditions. The results show a significant and large main effect of the loudspeaker configuration for all the tested attributes other than overall spectral balance and depth of field. The effect of visual stimuli was found to be small and significant for the attributes realism, sense of space, and spatial clarity. These results suggest that evaluations of audio-visual technologies aiming to evoke a sense of realism or presence should consider the influence of both the audio and visual modalities

Elicitation of expert knowledge to inform object-based audio rendering to different systems

Object-based audio presents the opportunity to optimise audio reproduction for different listening scenarios. Vector base amplitude panning (VBAP) is typically used to render object-based scenes. Optimizing this process based on knowledge of the perception and practices of experts could result in significant improvements to the end user's listening experience. An experiment was conducted to investigate how content creators perceive changes in the perceptual attributes of the same content rendered to systems with different numbers of channels, and to determine what they would do differently to standard VBAP and matrix based downmixes to minimize these changes. Text mining and clustering of the content creators' responses revealed 6 general mix processes: the spatial spread of individual objects, EQ and processing, reverberation, position, bass, and level. Logistic regression models show the relationships between the mix processes, perceived changes in perceptual attributes, and the rendering method/speaker layout. The relative frequency of use for the different mix processes was found to differ between categories of audio object suggesting that any downmix rules should be object category specific. These results give insight into how object-based audio can be used to improve listener experience and provide the first template for doing this across different reproduction systems

Secondary school educational practitioners’ experiences of school attendance problems and interventions to address them: A qualitative study

This is the author accepted manuscript. The final version is available from Taylor & Francis (Routledge) via the DOI in this record.School attendance problems are associated with a range of adverse consequences, and educational practitioners play a role in identifying and responding to attendance problems. This qualitative study explored educational practitioners’ experiences of working with students with attendance problems and interventions to address them. Focus groups were conducted with sixteen practitioners across three secondary schools. Data were analysed using thematic analysis. Attendance problems were considered resource-intensive and emotionally challenging. Practitioners expressed difficulty understanding causes, although individual/family factors were emphasised over school factors. A range of interventions were described, including adaptations to school context and providing emotional support. Views on punitive approaches were mixed. Individualised interventions implemented at the first sign of problems, and a team approach, were considered important. Findings highlight the important role of educational practitioners in identifying attendance problems and implementing interventions. Recommendations include early intervention, team-work, and emotional support for students with, and staff responding to, attendance problems.This work was supported by a PhD studentship from the University of Exeter Medical School, UK