Acoustic characteristics of outdoor spaces in an apartment complex

Many apartment complexes in Korea feature underground car parks releasing more of the landscape for residents’ leisure, rest, or conversation. The acoustic characteristics of these outdoor spaces can therefore make a significant contribution to the overall quality of the environment. This experimental study investigated the acoustic characteristics of outdoor spaces surrounded by multi-storey apartment buildings. In-situ measurements in three positions were carried out to evaluate the acoustic parameters, including reverberation time (RT), early decay time (EDT), rapid speech transmission index (RASTI) and sound pressure level (SPL) distribution. The results show that RT was generally rather long, over 4 sec at 500 Hz. On the other hand, RT at 125 Hz and 250 Hz was relatively short, about 0 to 3 sec. Above 500 Hz, RT increased with increasing source-receiver distance. EDT was longer than RT over a certain source-receiver distance at about 40 m. In terms of sound distribution, measured SPL was up to 8 dB higher compared to the semi-free field situation, indicating the effects of multiple reflections.