1,721,183 research outputs found
Analisi oggettiva e soggettiva degli effetti della posizione delle superfici fonodifondenti in sei diverse configurazioni di una sala da concerti
No full textL’importanza delle superfici fonodiffondenti in una sala destinata all’ascolto della musica è stata sottolineata da numerosi studi. Questo lavoro indaga gli effetti delle posizioni delle superfici fonodiffondenti sull'acustica delle sale da concerto utilizzando misure sul campo e valutazioni soggettive in una sala rettangolare. L’obiettivo è quello di chiarire la rilevabilità della loro presen-za e la posizione preferita dagli ascoltatori per diversi segnali, come strumenti musicali singoli, orchestra e rumore
Advances in diffusive surface design using 3D architectural parametric modeling programs
Full text linkDiffusive surfaces need to be optimally designed for both acoustic performance and aesthetic values. These aspects are at the heart of the design workflow and should respond to the requirements of both architects and acousticians. Advances in parametric modelling through digital tools have led to the integration of performance investigations and architectural design process. Moreover, parametric modeling software are also useful tools for manufacturing. Indeed, they can reduce the production time as they can easily be integrated inside the manufacturing process.
Although, it is more than a decade that the standard ISO 17497:2004 has proposed the scattering and diffusion coefficients measurements, further work is needed in order to increase designers’ awareness on diffusive surface design through simple design rules and approaches.
This research goes through three steps. First, it investigates the diffusive surface properties databases in order to extrapolate basic geometric guidelines for diffusive surface optimization. Second, it analyses a series of case-studies that apply the parametric modeling to the design of diffusive surfaces. Finally, it suggests a design process for diffusive surfaces by integrating parametric models and acoustic simulation aiming to provide architects and designers with rapid visual and acoustic feedback at a preliminary stage of their design
Long term monitoring of noise pollution in social gatherings places: time analysis and acoustic capacity as supports of management strategies
Full text linkCity of Torino (Italy), as many European cities, is facing noise pollution related to recreational noise of nightlife in open urban areas, such as streets, squares and terraces, where thousands of people meet spending all evening and night time. Noise from people speaking in these spaces can be very loud, due to crowd levels (since communication is possible only with a raised voice level) and people behavior.
This study shows the analysis of long term noise data collected in two years by a low-cost IoT network in San Salvario area. It highlighted regularities on night levels, mainly on a weekly basis with a seasonality.
Preliminary investigations on time series have been developed, in order to correlate noise levels and number of people involved, coupling environmental noise data and crowd sensors. Moreover, the concept of ‘Acoustic Capacity’ related to the noise levels has been investigated.
This approach based on a deeper quantitative knowledge is explored as an help to local administration and stakeholders in planning and implementing mitigation actions
INFLUENZA DI DIVERSI MATERIALI DI FACCIATA SULL' ACUSTICA DI UNO SPAZIO URBANO
Full text linkGli spazi pubblici rivestono un ruolo fondamentale all'interno della città e numerosi studi hanno riconosciuto una crescente importanza della percezione multisensoriale di tali spazi da parte degli utenti. In questa pluralità di sensi, l'udito gioca un ruolo fondamentale, dovuto alla sua qualità immersiva. Lo studio dell'ambiente esterno dal punto di vista acustico è ancora tuttavia legato molto spesso alla semplice riduzione del rumore ambientale. Così, l'involucro edilizio è studiato essenzialmente in relazione al fono isolamento degli ambienti interni e l'utilizzo di materiali fonoassorbenti in esterno, come facciate e tetti verdi, è stato indagato finora in relazione alla riduzione dei livelli di rumore da traffico. Tuttavia, il soundscape urbano è un'entità complessa, che riveste un ruolo che va al di là del semplice rumore ambientale, come riconosciuto recentemente anche a livello di normativa internazionale (ISO 12913-1:2014). È perciò necessario indagare come la scelta di diversi materiali di facciata possa influire sull'ambiente acustico esterno, il quale a sua volta influenzerà la percezione dello spazio da parte degli utenti. Il presente studio mira ad essere un primo passo in questa direzione, contribuendo ad aumentare la consapevolezza di architetti e urban planner su come l'involucro edilizio possa avere un'influenza sull'ambiente esterno sotto molteplici aspetti, e quindi a consentirne una progettazione più consapevole e "oggettivamente misurato" nei suoi effetti. Diverse simulazioni acustiche sono state condotte mediante il software ODEON 13.02 utilizzando il modello virtuale di una piazza di piccole dimensioni, precedentemente tarato utilizzando misure in campo. In tale modello, sono state variate le proprietà acustiche dei materiali di facciata degli edifici, ovvero i coefficienti di scattering e di assorbimento, basandosi su una banca dati di possibili materiali utilizzabili in esterno ricavata da letteratura esistente,per indagarne l'influenza sui parametri acustici calcolati in diversi punti della piazza, come tempo di riverberazione e livello di pressione sonora
Investigation on the diffusive surface modeling detail in geometrical acoustics based simulations
No full textThis study shows an investigation on the modeling level of detail of diffusive surfaces, which strongly influences the efficiency of geometrical acoustic based software. One diffusive condition of the lateral wall
of a shoebox hall has been modeled as (a) flat surfaces with surface scattering coefficient and (b) three-dimensional relief including edge diffraction. The analysis has been performed by comparing the conventional acoustic
parameters, which showed no significant differences, and by subjectively investigating the sensitivity of listeners to both modeling approaches, which highlighted that perceptual differences related to reverberance and spaciousness are clearer when using the modeling approach (b)
Measurement traceability of sound scattering coefficient of diffusive surfaces used in room acoustics and virtual acoustical environments
No full textThe best concert halls take benefit not only from the basic room shape but also from the corrugations of the walls. These diffusive surfaces are responsible for energy mixing, energy extraction from geometrical paths, for filling gaps and increasing reflections density in the impulse response. Hence, performance spaces are characterized by a complex sound field, due to the presence of absorptive and diffusive surfaces. The acoustic properties of these surfaces are characterized based on laboratory standardized measurements. Despite this, no sufficiently satisfactory databases exist. Thus, acousticians and practitioners alike rely on guidelines and experience to make their design choices. Based on this state of the art of diffusive surface design, the present work aims at giving more insight on their deployment by looking at the argument from a multidimensional point of view. First, it considers the estimation of the accuracy of the physical phenomenon measurements (only the random-incidence scattering coefficient has been considered), and further studies the effects of this accuracy on the objective room acoustic parameters, on the accuracy of simulation results and on perception. Knowing this interactions would give a measure of how much effort should be put into the acoustic characterization of diffusive surfaces and more freedom/ restrictions regarding the design of such surfaces could be determined. In Chapter 2, the experimental results aimed at providing a useful insight into the accuracy of the measurement procedure prescribed in the ISO 17497-1:2004 standard. The unsolved aspects of the measurements set-up have been systematically investigated and their contribution to the random-incidence scattering coefficient values has been estimated. It was found that some of these aspects contribute significantly to the measurement accuracy. In Chapter 3, in-situ evaluations of the acoustic effects that diffusive surfaces have on the objective room acoustic parameters have been investigated. To deepen such knowledge, acoustic measurements have been carried out in a variable-acoustic concert hall, the Espace de Projection, at the Institut de Recherche et Coordination Acoustique/Musique in Paris. The sensitivity of the sound field has been objectively investigated by observing the variation of the objective acoustic parameters, that is EDT, T30, C80, D50 and IACC, in either reflective and diffusive condition. It was found that some parameters are more affected by the degree of surface diffusivity, thus, its accuracy. In Chapter 4 has been investigated objectively the sensitivity of a virtual room sound field to the scattering coefficients accuracy. Two different prediction models have been used to simulate the sound field within a fan-shaped hall. It was found that some simulated parameters are affected by the random-incidence scattering coefficient accuracy, i.e. uncertainties of input data, which are higher than a limit value, lead to less reliable simulation results. In Chapter 5, an auditory experiment has been conducted to highlight some perceptual aspects regarding the use of diffusive surfaces in concert halls. These results provide more insight and help to understand whether listeners perceive the presence of diffusive surfaces, and how this perception is scattered throughout the audience area. Furthermore, the study is aimed at determining the objective measurements of a sound field which best correlate to the subject's perception. This would give the measure of how much effort should be put into the determination of the diffusive properties of surfaces, and which could be the variables to relate in an analytic equation, which could readily express the effects of diffusion in room acousti
Effetto delle riflessioni diffuse sulla risposta all'impulso in un ambiente semianecoico
No full textArcheoacustica: innovazioni tecnologiche per la riscoperta del teatro antico
No full textIl teatro antico rappresenta uno dei lasciti più consistenti ereditati dalla cultura greco-latina. Malgrado sia già avvenuta una presa di coscienza relativamente alla sua conservazione e valorizzazione, esplicitata attraverso diverse Carte del Restauro, la grande maggioranza delle strutture teatrali a noi sopravvissute versa in condizioni disastrate e compromesse dal tempo e dagli agenti atmosferici, senza contare le sovrapposizioni dovute alle espansioni degli agglomerati urbani. Pertanto, la parziale mancanza di elementi architettonici e lo stato di abbandono di molti teatri italiani rendono difficile, se non impossibile, la ricostruzione dei loro apparati teatrali originali. Altrettanto compromessa ne è l'acustica: concepite come vere e proprie macchine per l'ascolto, attualmente i teatri in grado di ospitare una performance e di assolvere correttamente al proprio compito acustico sono un numero estremamente limitato. Per questo motivo, si è esplicitata la necessità di ricevere ausilio dalle nuove tecnologie in sviluppo, sia a sostegno dell'attività teatrale in situ (e.g. impianti elettro-acustici, conchiglie d'orchestra), sia a favore di una maggiore comprensione della sua intima natura sonora e della sua divulgazione in campo scientifico. Partendo da questi spunti, sono stati messi in discussione l'approccio e la metodologia di analisi del campo sonoro per il teatro antico, consolidatosi negli anni passati grazie al progetto europeo ERAT
Ergun-Wu equation: a novel approach for the determination of physical parameters in low/medium porosity materials.
No full textThe experimental determination of effective porosity and tortuosity in medium/ low porosity materials (typically ≤0.5) is still a challenge debated in
metrology. In this paper is proposed a semi-empirical approach to the problem, based on the implementation of a new resistive model and accurate
experimental input data. The empirical model is based on the recent redefinition of Ergun’s equation (Wu et al., 2008) and on the geometric model for tortuosity (Yu et al., 2000). On the basis of measured quantities, such as the airflow resistivity and the average pore diameter, it is possible to
determine the average effective porosity and the average tortuosity of the
material in a defined range with a proper confidence level. In this work is
also addressed the problem of a suitable determination of the average pore
diameter and a definition of an average equivalent pore diameter in fibrous
materials is also proposed
Development of the Albanian translation of the Perceived Affective Qualities in the ISO/TS 12913-2 soundscape standard
No full textThe Perceived Affective Qualities (PAQs) outlined in the ISO/TS 12913-2:2018 standard have been translated into many languages and are referred to as a global standard to evaluate the acoustic environment in various contexts. There is a growing legislative framework in Albania that addresses noise pollution through Law No. 9774 and Guideline No.8. The aim of this study, which recognizes the increasing trends in acoustic research in Albania, and acknowledges the gap regarding soundscape descriptors has been to develop equivalent versions of the soundscape descriptors defined in ISO/TS 12913-2:2018 by translating the PAQs into the Albanian Language through a model fitting approach. This study, which has followed the Soundscape Attributes Translation Project (SATP) guidelines, has employed a mixed method, that is, both a qualitative investigation and a quantitative evaluation based on specific criteria built upon previous work, have been conducted. In the first phase (1a), eight linguistic experts independently translated eight affective attributes, which were later verified in the second phase (1b) by acoustic experts. After three potential translations had been generated for each of the eight PAQs, a quantitative approach, namely phase (1c), which had been proposed in previous SATP studies, was employed. Thirty-two native Albanian individuals, all of whom were proficient in English, evaluated the translated candidate terms in an online questionnaire, considering such criteria as their Appropriateness, Understandability, Clarity, Antipodal Antonymity, Orthogonal Unbiasedness, Connotativeness, Non-connotativeness, and Implicative Balance. The collected data were then subjected to a series of Kruskall Wallis tests with Bonferroni corrections to determine the final translation for each PAQ. In conclusion, eight Albanian attribute translations have been defined. Despite some limitations, our findings are promising and suggest that the selected attributes are validated inputs to the next steps of the research which involve listening experiments (SATP phase 2)
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