Evaluation of acoustic measurements methods and design of meeting rooms: solutions for an optimal speech perception

A quite large variety of software appears useful to calculate interesting parameters for the rooms’ acoustics quality, after previous receiving of input data. In phase of measurements, it is necessary to set correctly the equipment and remind each time the used settings, in order to guarantee both the repeatability and the reproducibility of the measures, even using a different software. ODEON is a specific software used world-wide for prediction of room acoustics: given a 3D-model, the acoustics can be predicted and represented. The first part of this research aims to test the validity of ODEON software not only as a simulation tool, but also as a useful measurement tool, firstly by verifying rooms acoustic features in their current conditions. A first sample of study cases was analyzed in Turku (Finland), using the Turku University of Applied Sciences’ equipment and ODEON 14. This sample includes two categories of rooms, also mentioned in the ISO 3382 standards classification: open plan offices and auditoria, the latter meant as a presentation space used for speaking in public. In Turku, the measurements were taken using both ODOEN and SoundBook, a universal portable measuring system for acoustic. The comparison between two methods leads to achieve a more specific range of data for the investigated parameters. A second sample of rooms was then measured and analyzed in Turin (Italy), using the Politecnico di Torino’s equipment and ODEON 13. The comparison of these results is carried out both with Adobe Audition’s Aurora, and ODEON 15’s simulations system. The purpose was to understand how ODEON measurements system is reliable: the investigated software’s methodology appears a good tool in terms of practicality, learning process, economics and transport. The further comparison of cases measured through other software gives ODEON even more reliability: it can be used in a wider way, also counting on the easy process of output data for analysis. It works giving good results only if a previous calibration is correctly made. The second part of the thesis is focused on the acoustic design of two cases study, both used as interaction and presentation rooms: 1.??The Cafaro meeting room, in Politecnico di Torino’s headquarters; 2.??The Galfer meeting room, in “Galileo Ferraris” Politecnico’s branch. In these spaces, the understanding and perception of speech represents the main requirement to satisfy. The first step for the treatment was measuring them in unoccupied and untreated conditions: for this purpose, two methods were used and later compared (ODEON’s measurements system and Adobe Audition’s Aurora). In this way a more accurate starting evaluation was defined, through comparison of the achieved results. The data were analyzed, as a second step, in order to decide their reliability. Results were compared also to those achieved through the ODEON’s simulation system: it’s extremely important to control and manage the absorption coefficients of all the surfaces’ materials found in the room. After calculating the required chosen absorbers and diffusers surface, the necessary number of panels is found as output. These panels were positioned in the rooms following rules pointed out in technical literature. The above-mentioned research outlined a design workflow, useful for architects and engineers to design better sounding meeting rooms.