Dpto. Física - Fisika Saila

Permanent URI for this community

http://hdl.handle.net/2454/10451

Browse

Browsing Dpto. Física - Fisika Saila by Author "Arana Burgui, Miguel"

Now showing 1 - 4 of 4
  • Thumbnail Image
    PublicationOpen Access
    Are urban noise pollution levels decreasing?
    (Acoustical Society of America, 2010) Arana Burgui, Miguel; Física; Fisika
    The majority of acoustic impact studies developed over the last 50 years have used a similar acoustic parameter Leq, Ldn but the noise mapping methodology has been very uneven. The selection of the measurement points, the measurement periods, or the evaluation indices have not followed a unique criterion. Therefore, it is not possible to compare the sound pollution levels between different cities from those studies, at least in a rigorous sense. Even more, different studies carried out in the same city by different researchers during different years and using different methodologies are not conclusive whether the acoustic pollution increases or decreases. The present paper shows results, with statistical significance, about the evolution of the acoustic pollution obtained for two Spanish cities, Pamplona and Madrid. In both cases, it can be concluded that noise pollution decreases over time (P<0.01).
  • Thumbnail Image
    PublicationOpen Access
    People exposed to traffic noise in european agglomerations from noise maps: a critical review
    (De Gruyter, 2014) Arana Burgui, Miguel; San Martín Murugarren, Ricardo; Salinas Hilburg, Juan Carlos; Física; Fisika
    Two of the main objectives of the European Directive on environmental noise are, firstly, to unify acoustic indices for assessing environmental noise and, secondly, to standardize assessment methodologies. The ultimate goal is to objectively and comparably manage the impact and evolution of environmental noise caused both by urban agglomerations and by traffic infrastructures (roads, rails and airports). The use of common indices and methodologies (together with five-year plan assessment required by the authorities in charge) should show how noise pollution levels are evolving plus the effectiveness of corrective measures implemented in the action plans. In this paper, available results from numerous European agglomerations (with particular emphasis on Spanish agglomerations) are compared and analysed. The impact and its evolution are based on the percentage of people exposed to noise. More specifically, it demonstrates the impact caused by road traffic, which proves to be the main noise source in all agglomerations. In many cases, the results are extremely remarkable. In some case, the results are illogical. For such cases, it can be concluded that either assessment methodologies have been significantly amended or the input variables to the calculation programs have been remarkably changed. The uncertainty associated with the results is such that, in our opinion, no conclusions can be drawn concerning the effectiveness of remedial measures designed within the action plans after the Directive’s first implementation Phase.
  • Thumbnail Image
    PublicationOpen Access
    Strategic noise map of a major road carried out with two environmental prediction software packages
    (Springer Netherlands, 2010) Arana Burgui, Miguel; San Martín Murugarren, Ricardo; San Martín Erviti, María Luisa; Aramendía Santamaría, Emilio; Física; Fisika
    The main objective of this study is to analyze the differences found in the results of noise mapping using two of the most popular software techniques for the prediction of environmental noise. The location selected to conduct the comparative study is an area encompassed by the ring road that surrounds the city of Pamplona and on a grid, with a total of 6 × 105 points, approximately. In fact, and as the Environmental Noise Directive points out, it is a major road designated by a Member State (Spain). Configuration of the calculation parameters (discretization of the sources, ground absorption, reflection order, etc.) was as equivalent as possible as far as programs allow. In spite of that, a great number of differences appear in the findings. Although in 95.5% of the points the difference in the noise level calculated from the two programs was less than 3 dB, this general statistic result concealed some great differences. These are due to the various algorithms that programs implement to evaluate noise levels. Most differences pertain to highly screened receivers or remote ones. In the former, the algorithm of visibility is the main cause of such differences. In the latter, differences are mainly brought about by a different implementation of the propagation under homogeneous and favorable atmospheric conditions from both software systems.
  • Thumbnail Image
    PublicationOpen Access
    Uncertainties caused by source directivity in room-acoustic investigations
    (Acoustical Society of America (ASA), 2008) San Martín Murugarren, Ricardo; Arana Burgui, Miguel; Física; Fisika
    Although deviations in the measurement of acoustic parameters should be lower than the subjectively perceivable change in the corresponding parameter measured, this study reflects that directionality of sound sources could cause wide audience areas to break away from this criterion at high frequencies, even when using dodecahedron loudspeakers which meet the requirements of the ISO 3382 standard. The directivity of four different acoustic sources was measured and the influence of its accurate orientation spatially quantified in five enclosures for speech and music. By means of simulation software, the number of receivers affected by uncertainties greater than difference limens was established.