Evaluating water sounds to improve the soundscape of urban areas affected by traffic noise

The acoustic characteristics of various kinds of water sounds were investigated to evaluate their suitability for improving the soundscape with road traffic in urban spaces. Audio recordings were made in urban spaces with water features such as fountains, streams, water sculptures, or waterfalls. The temporal and spectral aspects of the sounds were clarified, and subjective evaluations were performed to find the proper level difference between water sounds and road traffic noise for making urban soundscape more subjectively pleasant. The results indicated that the perceptual difference of the water sound level was around 3 dB with noises from road traffic in the background. The water sound, which had 3 dB less sound pressure level, was evaluated as preferable when the levels of road traffic noise were 55 or 75 dBA. It was also found that water sounds with relatively greater energy in low-frequency ranges were effective for masking noise caused by road traffic. The results of the present study will be valuable to urban designers and planners by providing guidelines for improving design solutions for water features in urban soundscape. (C) 2010 Institute of Noise Control Engineering.