Conference_programme: 18: Room acoustics
Lecture: Applied measurements process for improving room acoustics in children day-care centre
Author(s): Šubic Nika, Dovjak Mateja, Košir Mitja, Pajek Luka, Božiček David, Potočnik Jaka, Prislan Rok, Repše Ana, Kunič Roman
Summary:
Aim: Acoustic environment of day-care facilities is often unacceptable - reverberation times (RT) are usually higher than recommended, which has a negative effect on the equivalent sound pressure level (Leq). The main objective of the study was to find an acoustically suitable solution that would not present an economical strain or health risk for the users of the institution in question.\nMethods: A thorough acoustical evaluation and renovation of a selected playroom was conducted as a part of this study. Firstly, the assessment of the current state was made by means of measurements of RT, followed by selection of absorber materials on the basis of impedance tube testing and prediction of the RT with analytical calculations. Ultimately, a gradual application of the prototypical absorbers into the aforementioned space was performed, accompanied with measurements of RT (100 Hz – 10000 Hz) and Leq.\nResults: Impedance tube tests show excellent acoustical properties (α ≈ 1.0) of the chosen felts, especially thicker versions (8 cm). Some high frequency absorptivity was lost when covering the material with a nonporous layer. Analytical calculations were conservative; the actual absorption surface was reduced based on the results of intermediate RT measurements. A significant drop of almost 44% in RT from 0.92 s to 0.52 s (400 Hz – 2500 Hz) was measured after the installation of all acoustical elements, along with a noticeable drop in RT of approximately 0.21 s when merely half of the absorbers were placed into the room. Placement of acoustic absorbers only on the ceiling proved as unsatisfactory. Leq dropped by 2.5 dB after the renovation.\nConclusion: The applied measurements process proved as a fairly quick, economical and precise solution that produced quality results. Such prediction technique of room acoustics does require some engineering sense, but nevertheless produces satisfying results when working with typical spaces.
Corresponding author
Name: Ms Nika Šubic
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Country: Slovenia
