Measurement and Subjective Assessment of Water Generated Sounds

There is increasing concern with protecting quiet and tranquil areas from intrusive noise. Noise reduction at source and barriers to transmission are mitigation measures often considered. An alternative is to attempt to mask or distract attention away from the noise source. The masking or distracting sound source should be pleasant so that it does not add to any irritation caused by the noise source alone. The laboratory measurements described in this paper consisted of capturing under controlled conditions the third octave band spectra of water falling onto water, gravel, bricks and small boulders and various combinations. These spectra were then matched with typical traffic noise spectra to assess the degree of masking that could be expected for each option. Recordings were also taken during each measurement and these were used later to enable the subjective assessment of the tranquillity of the sounds. It was found that there were differences between water sounds both in terms of masking and their subjective impact on tranquillity.