Acoustics Of Classrooms

In this article we will study sound—specifically, how sound allows us to communicate in a classroom and how we can improve that communication. You will learn how sound is measured and how people called acoustics engineers help architects and designers to make sure classrooms are not too noisy—or too quiet. We even have some experiments that you can do to measure sounds at home, at school, or in a football stadium

Attack Of The Drones’ Exploration Of The Sound Power Levels Emitted And The Impact Drone’s Could Have Upon Rural Areas

This study considers the acoustic emission from a DJi Phantom 4 commercial drone using different rotor blades. Measurements were taken from a hovering drone with four commercial product blade configurations. Measurements were taken in accordance with (BS) EN ISO 3745: 2009 ‘Acoustics – Determination of sound power levels and sound energy levels of noise sources using sound pres-sure – Precision methods for anechoic rooms and hemi-anechoic rooms’. The aim of the project was to consider the sound characteristics emitted, specifically tonality and to determine the dis-tance a drone could be heard from, with the different blade configurations, in a rural setting. By considering the different blade configurations within a rural setting, the role drones have within society is considered

Remote sensing of intertidal morphological change in Morecambe Bay, U.K., between 1991 and 2007

Tidal Flats are important examples of extensive areas of natural environment that remain relatively unaffected by man. Monitoring of tidal flats is required for a variety of purposes. Remote sensing has become an established technique for the measurement of topography over tidal flats. A further requirement is to measure topographic changes in order to measure sediment budgets. To date there have been few attempts to make quantitative estimates of morphological change over tidal flat areas. This paper illustrates the use of remote sensing to measure quantitative and qualitative changes in the tidal flats of Morecambe Bay during the relatively long period 1991–2007. An understanding of the patterns of sediment transport within the Bay is of considerable interest for coastal management and defence purposes. Tidal asymmetry is considered to be the dominant cause of morphological change in the Bay, with the higher currents associated with the flood tide being the main agency moulding the channel system. Quantitative changes were measured by comparing a Digital Elevation Model (DEM) of the intertidal zone formed using the waterline technique applied to satellite Synthetic Aperture Radar (SAR) images from 1991–1994, to a second DEM constructed from airborne laser altimetry data acquired in 2005. Qualitative changes were studied using additional SAR images acquired since 2003. A significant movement of sediment from below Mean Sea Level (MSL) to above MSL was detected by comparing the two Digital Elevation Models, though the proportion of this change that could be ascribed to seasonal effects was not clear. Between 1991 and 2004 there was a migration of the Ulverston channel of the river Leven north-east by about 5 km, followed by the development of a straighter channel to the west, leaving the previous channel decoupled from the river. This is thought to be due to independent tidal and fluvial forcing mechanisms acting on the channel. The results demonstrate the effectiveness of remote sensing for measurement of long-term morphological change in tidal flat areas. An alternative use of waterlines as partial bathymetry for assimilation into a morphodynamic model of the coastal zone is also discussed

Recomendações de Secretários de Educação para um novo marco sobre responsabilização educativa ao nível federal

The members of the Large Countywide and Suburban District Consortium—a group of large, highly diverse, and successful districts across the country—have made great strides in achieving college and career readiness for all students. While they are succeeding, the consortium proposes that more could be done to accomplish their objectives through collaboration with Congress to establish federal policy and laws aligned with practices that foster college and career ready outcomes at scale. This article, introduced by Baltimore County Public Schools Superintendent S. Dallas Dance, proposes the critical principles that should undergird a new federal approach to state and district accountability. Los miembros del Consorcio Large Countywide and Suburban District -un grupo de distritos escolares de gran tamaño, muy diversos, y con éxito en todo el país, han conseguido grandes avances en la preparación universitaria y profesional de todos los estudiantes. Mientras el consorcio está satisfecho con estos logros, propone que se puede hacer más para lograr sus objetivos a través de procesos de colaboración con el Congreso Nacional para establecer una política federal y sancionar leyes en consonancia con prácticas que mejoren las preparación universitaria y profesional de todos los estudiantes a escala nacional. En este artículo, preparado por el Secretario de Instrucción Pública del Condado  de Baltimore S. Dallas Dance, propone los principios fundamentales que deberían sustentar una un nuevo enfoque federal para un programa de modelos de responsabilidad educativa a nivel de los distritos y estados.Membros do Consórcio Large Countywide and Suburban District, um grupo de grandes, distritos escolares com uma população muito diversa, e com sucesso em todo o país têm feito grandes progressos na preparação dos estudantes para estudos universitários e para carreiras profissionais de todos os alunos. Embora o consórcio esteja satisfeito com essas conquistas, propõe que se pode fazer mais para alcançar seus objetivos através de processos de colaboração com o Congresso Nacional para estabelecer uma política federal e promulgar leis em conformidade com as práticas que melhoram a preparação dos estudantes para estudos universitários e para carreiras profissionais em todo o país. Neste artigo, elaborado pela Secretaria de Educação Pública do Condado de Baltimore S. Dallas Dance propõem os princípios fundamentais que devem sustentar uma nova abordagem federal para um programa de responsabilização educativa ao nível dos distritos e dos estados

Face the Music: A before and after study of the hearing acuity of Classical music students

Since the implementation and enforcement of the European Union Physical Agents Directive (Noise) the Acoustics Group has collaborated with the Royal Academy of Music creating the noise team formed from administrators, scientists, and senior management. Our challenge was to allow these highly talented artists to practice, rehearse, and perform safely during their time at the Royal Academy of Music. This ten year project involved more than 3000 musicians measuring sound exposure of each instrument group and the hearing acuity of every student, as well as hearing surveillance of a sample of graduates. At each occurrence the students were questioned as to their aural environment. The paper will focus upon the hearing acuity of graduates after studying music for a period of four year

Facing the music: Helping classical musicians comply with the Control of Noise at Work Regulations

© 2016, German Acoustical Society (DEGA). All rights reserved. Since the implementation and enforcement of the European Union Physical Agents Directive (Noise) the Acoustics Group has collaborated with the Royal Academy of Music. Over the past nine years more than 2600 students have had their hearing tested and all instrument groups have undergone dosimetry to establish typical sound dose over a working day. The paper will focus upon the hearing acuity of the musicians and solutions to help the classical music students comply with the regulations. The challenge was to allow these highly talented artists to practice, rehearse, and perform safely. Our job as acousticians is to ensure that they are able to

Acoustic conditions in orchestra pits: are metadiffusers a potential solution?

Rising concerns about public health and safety have progressively induced a change in control of noise regulations, specifically on those applicable to the work environment. These directives have been developed to protect employees from harmful side effects of their working conditions, firstly targeting high noise levels generated by heavy machinery in industry. Nowadays, noise control regulations are widely effective and applicable to nearly all working environments, including institutions dedicated to the arts, such as opera houses. To the latter, directives on noise control are of major concern as opera performances tend to generate very high sound levels, especially in the area of the orchestra pit – the sunken space between stage and audience. In such context, management faces a difficult task conforming to noise regulations as they must balance the sometimes competing demands to (i) dutifully protect their employees – musicians and others – from any harmful ‘sounds’ or ‘noise’ that might be generated, and (ii) deliver world-class operatic art for the public, where noise regulations might compromise the culture of the art form. ‘Sound’ and ‘noise’ are two terms of intense interest when dealing with control of noise regulations in the entertainment sector. Indeed, noise is generally described as ‘unwanted’ sound, judged as unpleasant, whereas music is considered most of the time as a ‘desirable’ and pleasant sound; leading to a debate on the pertinence of noise regulations within the musical arts. Such debate has recently been discussed in the High Court in London, where the court favoured an orchestral viola player who claimed to have suffered noise induced hearing loss during a rehearsal of Wagner's Valkyrie1; the major argument being that the opera house exceeded industry-wide standards on noise control, viz. daily LAE > 85 dBA. Such a case has no precedent in UK history, raising concerns for other opera houses and music spaces on how to enforce noise regulations without affecting the performances’ nature. This leads to the question of whether noise control regulations should apply to all industries, regardless of the type of sound they generate

A deployed multi agent system for meteorological alerts

The Australian Bureau of Meteorology has a requirement for complex and evolving systems to manage its weather forecasting, monitoring and alerts. This paper describes a system that monitors in real time the current terminal area forecasts (forecasts for areas around airports) and alerts forecasters to inconsistencies between these and observations obtained from automatic weather station (AWS) data. The contributions of the paper are a description of the overall architecture including legacy components, and the mechanisms that have been used to interface to legacy components; a description of an inferencing mechanism, available in recent versions of the JACK Intelligent Agents toolkit which has been particularly useful in some of the reasoning needed in this application; and a detailed description of the architecture for data sharing and data management. The system is currently deployed and a project is underway to extend this to a much larger system