| Keywords |
Aluminum Profile ; Sound Absorption Coefficient ; Scattering Coefficient |
| Abstract |
To control the room acoustics of a multipurpose hall, finishing materials that can control the absorption and diffusion properties are needed. This study uses aluminum profiles to investigate the sound absorption and diffusion properties as air space increases in differing diffusion forms. Sound absorption coefficient was measured using the impedance tube method and reverberation room method. Also, the scattering coefficients depending on the aluminum profiles were measured in a scaled reverberation room (1/5 scale). The impedance tube method sound absorption coefficient increased in the low-mid frequency ranges (800-100 Hz) where the aluminum profile and the increase in air space acted as a resonance type absorber. The sound absorption coefficient measured by the reverberation room method increased in the low-mid frequency ranges (630-800 Hz), which is lower than the resonant frequency, as the back air space was increased from 40 mm to 150 mm. Air space increases sound absorption in the frequency ranges over the resonant frequency (2000-4000 Hz), and also decreases the difference in sound absorption coefficients in various frequencies. Scattering coefficient was over 0.5-0.65, similar to the scattering coefficient at high frequency ranges (over 2000 Hz) in a semi-sphere. Therefore, it shows that Aluminum Profiles are effective as profile acoustical diffusers when considering both absorption and scattering performances. |