A group from the UVA is researching acoustics in industry, building, and the environment
Cristina G. Pedraz/DICYT The Acoustic and Applied Vibrations (Acústica y Vibraciones Aplicadas, AVISA) Recognised Research Group (Grupo de Investigación Reconocido, GIR) of the University of Valladolid (UVA) is working on various lines of research concentrating on acoustics and vibrations in the fields of industry, building, and the environment. The GIR was established in April last year and consists of the lecturers of the School of Industrial Engineering María Ángeles Martín Bravo (who is the Group coordinator) and Ana Isabel Tarrero Fernández, together with the lecturer of the School of Architecture María Machimbarrena. The group enjoys the collaboration of the lecturers Marta Herráez and Lara del Val, also from the School of Industrial Engineering, and of the PhD student Carolina Monteiro.
Several studies have shown that background noise affects human health in a number of ways. It may cause sleeping disorders or reduce cognitive performance, but it may also trigger other more serious problems such as alterations to the cardiovascular system (which increases the risk of heart disease or arterial hypertension), the endocrine glands, the digestive system, or psychic problems. Noise may also affect the environment, as the alteration of animal habitat may lead to changes in ecosystems.
The Group of the UVA is aware of this problem and its objectives include the raising of public awareness of the problems that may be caused by background noise and research into various aspects of soundproofing.
As far as research is concerned, one of the projects on which the Group has been working in recent years was the so-called COST TU0901 (Scientific Programme on Integrating and Harmonizing Sound Insulation Aspects in Sustainable Urban Housing Constructions), an initiative that aimed to integrate and harmonise soundproofing parameters in European building, given the diversity of regulations and requirements in the various countries (http://www.dicyt.com/noticias/la-universidad-de-valladolid-lidera-un-proyecto-europeo-sobre-aislamiento-acustico-de-edificios).
The project ended in late 2013 but opened up many other avenues. As María Machimbarrena and the PhD student of the group Carolina Monteiro explain, work is continuing on various fronts. "As part of the project we drew up a proposal for descriptors of soundproofing and impact noise. We considered how we could continue to encourage European countries to use these common descriptors and we proposed a transfer of the values. Each country now has its own indicators and transfer is necessary to find out the correspondences”.
To carry out this transfer the Group is using a large database courtesy of the Institute for Sustainable Construction (ISC) of the Napier University of Edinburgh in the UK. The work is complex, since as the researchers “it depends to a great extent on building types”.
Plan for the acoustic classification of housing
On the other hand, there is currently a European directive for energy efficiency and saving in construction, which establishes a 2020 deadline for all buildings to comply with certain sustainable energy parameters. Through the COST TU0901 project the researchers have also put forward a proposed plan for the acoustic classification of housing.
“It was observed that acoustics in building are being systematically overlooked in European directives, and an attempt has been made to arouse and to motivate the administrations to take this into account in the future, as the energy and acoustic characteristics of a building may be very closely linked. After four years of work on the existing acoustic classification systems, a proposal for the acoustic classification of housing has been launched to be debated by the International Standard Organization (ISO) so that in the future there will be a harmonised acoustic classification system that can be used by all EU countries, either as a recommendation or as a regulation.”
As part of the project it is necessary to be able to transfer the soundproofing descriptors existing in each country into "harmonised and agreed" descriptors that will be used in the acoustic classification plan. For this reason it is necessary to provide a simple descriptor transfer system to be used in each country. However, the drawing up of these transfers leads to discrepancies as some propose merely mathematical transfers and others propose transfers depending on building types. The UVA researchers also advocate the inclusion of users in this discussion on the frequency ranges and the descriptors, taking into account their perception. As part of Carolina Monteiro's thesis, perception tests have been carried out on soundproofing. “We want to find out whether the descriptors, which are objective numbers, actually represent people's subjective perception”, she emphasises.
Two books and a new project
Finally, also within the framework of COST TU0901 two books have been published: one on the results of the project and the proposals that have been launched (of descriptors of soundproofing, of the plan for the acoustic classification of housing, and of the descriptor transfer process); and a series on construction in Europe in which each country has contributed in keeping with its possibilities to the evolution of its building type over time and the acoustic characteristics of these old and new constructions, pointing out design problems and errors of execution.
Moreover, the Group will also take part in a new COST project, namely TU1303 (Novel structural skins: Improving sustainability and efficiency through new structural textile materials and designs), which concentrates on new façade structures. It is a case of contributing the acoustic element to the initiative, concentrating on the heat and energy sector. The project began in 2013 and will be developed until November 2017.
The impact of environmental noise on protected areas
Likewise the Acoustics and Applied Acoustics Group has just started a new line of research into the environmental impact of noise on protected natural areas. It is a case of researching the effects associated with noise of anthropogenic origin (generated by man, for example owing to the construction of infrastructures or leisure activities) in these protected areas. Acoustic zoning studies and work on the identification of sound landscapes is also planned.