Measurement of Temporal and Spatial Factors of a Flushing Toilet Noise in a Downstairs Bedroom
Toshihiro Kitamura, Ryota Shimokura, Shin-ichi Sato and Yoichi Ando

In a three-floored apartment, located in a quiet living area of Kobe, one resident was very annoyed by the flushing noise of an upstairs toilet that could be heard in the downstairs bedroom. The resident accused the construction company of improper construction, although the sound pressure level was only about 35 dBA. The purpose of this study is to clarify the characteristics of a flushing toilet noise in a bedroom on the downstairs floor in terms of the temporal and spatial factors extracted from the autocorrelation function and cross-correlation function based on the model of the human auditory-brain system [Ando, Y. (1998). Architectural Acoustics -Blending Sound Sources, Sound Fields, and Listeners: AIP Press/Springer-Verlag, New York].
The results of the measurement showed that the temporal and spatial factors for the flushing toilet noise changed dramatically as a function of time. According to the human auditory-brain system, temporal factors of sound signals are processed by the left hemisphere, and spatial factors of sound signals are processed by the right hemisphere. The flushing noise of an upstairs toilet stimulates dramatically both the left and right hemispheres, which are sensitive to change in both the temporal and spatial factors.

Key words: noise measurement, flushing toilet noise, the model of auditory-brain system