The scattering coefficient has become a determinant parameter in Architectural Acoustics, in particular in room acoustic software because it enhances the precision of simulation results. Although there is a wide agreement on the necessity of using scattering coefficients for characterizing surfaces and pattern elements within an enclosed space, such as a concert hall, there is still a lack of knowledge on the influence of this on the human perception. The primary purpose of this project is to investigate how changes in scattering coefficients of diffusing surfaces could possibly affect the perception of music among the audience in concert halls.

Related topics: Architectural Acoustics, Psychoacoustics, Measuring Techniques in Acoustics

The scattering coefficient offers a handy description of diffuse reflections of the sound field: it is defined as the ratio of the non-specularly reflected sound energy to the totally reflected energy. In recent years, the scattering coefficient has been more and more integrated in room acoustics computer simulation as it significantly improves the precision and accuracy of simulation results. Nowadays, the available scattering coefficient data are mainly related to architectural surfaces with different patterns and structures. A lot of effort has also been put on the determination of numerical methods for calculating this coefficient beforehand. Despite all, investigation on common objects has rarely been performed and there is still a lack of scattering coefficient data, especially for items that are commonly present in closed spaces, such as chairs, desks, bookshelves. This project is a first step for filling this gap.

Related topics: Architectural Acoustics,Measuring Techniques in Acoustics
External link: Scattering Coefficient Open Database

Scattering is an important factor in room acoustic simulations. It defines the amount of diffuse sound within a simulated enclosed space. In recent years, the effort in obtaining proper scattering coefficients, both by means of measurements and numerical simulations, has more and more increased. However, the extent to which variations of the scattering coefficients are audible remains unclear. This projects aims to quantify the just noticeable difference for different scattering coefficients associated to lateral walls of auralized concert halls and tries to determine the influence on sound and music perception due to variations in scattering coefficients.

Related topics: Architectural Acoustics, Psychoacoustics

Omnidirectional sources represent an integral part of acoustic measurement systems as their acceptance, particularly for dodecahedron loudspeakers, has become almost universal. For higher frequencies, the radiation pattern of an omnidirectional source loses homogeneity, since its directivity diverges significantly from an ideal spherical shape. As a consequence, the final measurement is affected by inaccuracies that can be expressed in terms of uncertainty. This project developed a model to quantify the influence of the source directivity on the measurement uncertainty.

Related topics: Architectural Acoustics, Measuring Techniques in Acoustics

The object of this project was to describe how temporal and dynamic cues in knocking sounds communicate emotions, just like in musical performances. Several emotions were supposed to be expressed by different performers and judged in randomised tests by other listeners, whose ability to perceive the intended emotions was evaluated. Together with acoustic measurements, arm movements during the knocking action were detected, so that the body behaviour (visual component) can be correlated to the sound evaluation (acoustical component). Results indicated that there is a connection between gesture and emotion, and the intended emotions were generally perceived correctly.

Related topics: Music Communication, Psychoacoustics

This project address the question whether it is the acoustics of the space where monks usually pray by singing that has determined the executive approach, or whether the aesthetics of Gregorian chant originated in other contests and was adapted to the acoustical characteristics of the space where it is expressed. The results of an acoustics characterization of the chant and the environment were analyzed with particular reference to the reduction of the modulation index. Moreover, an extensive analysis on pitch variations in singing of famous european scholae cantorum was also performed.

Related topics: Architectural Acoustics, Psychoacoustics, Measuring Techniques in Acoustics