Auditory masking

The term auditory masking implies that a sound (masker sound) influences the perception of another sound (target sound), so that the focus shifts from the target to the masker sound¹. There are two general types of auditory masking; energetic and informational. In energetic masking, the target sound is rendered inaudible or less loud. In informational masking, both sounds are audible but the main focus lays on the masker sound. Masking is a complex phenomenon that depends on several cues for successful implementation, including physical characteristics of sound sources and their relative location in space². Some scientists suggest that it is not fruitful to use this strategy if the sound pressure level exceeds 65-70 dBA³. If the intention is to achieve tranquil qualities, significantly lower levels than this is required in most cases^4,5. A possible exception is when tranquillity is associated with social seclusion, in which case it may be desirable to have higher sound pressure levels in order to obstruct (spoken) communication⁶.

 

References:
¹Moore, B.C.J.. An introduction to the psychology of hearing. Bingley: Emerald, 2012.
²Cerwén, G.. Urban soundscapes: A quasi experiment in landscape architecture. Landscape Research 41 (5), 2016, 481-494.
³Zhang, M. & Kang, J.. Towards the evaluation, description, and creation of soundscapes in urban open spaces. Environment and Planning B-Planning & Design, 34(1), 2007, pp. 68-86.
⁴Pheasant, R.J., Fisher, M.N., Watts, G.R., Whitaker, D.J. & Horoshenkov, K.V.. The importance of auditory-visual interaction in the construction of ‘tranquil space’. Journal of Environmental Psychology, 30(4), 2010, pp. 501-509.
⁵Nilsson, M.E. & Berglund, B.. Soundscape Quality in Suburban Green Areas and City Parks. Acta Acustica United with Acustica, 92(6), 2006, pp. 903-911.
⁶Whyte, W.H.. The social life of small urban spaces. Washington, D.C.: The Conservation Foundation, 1980.