People perceive various phenomena in their living space, whether natural or artificial.
The most typical phenomenon is vibration, and sensory vibration and sound fall into this category.
The unit expressed in terms of vibration has a frequency (or frequency of oscillation), which is related to how people are receptive, etc.
The figure below shows the commonly recognized range of vibration and sound.
Figure Frequency range of vibration and sound
We are involved in the frequency range excluding ultrasound.
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(1) Frequency (frequency)
A periodic phenomenon, the number of times the same condition is repeated per second.
The unit is Hz (hertz, Hz=1/T, T: period (s or seconds)).
(2) Very low frequency sound
A sound below 20 Hz, inaudible to humans. It may be physically felt.
(3) Human Audible Voice
Sound that can be heard by humans, from 20 Hz to 20 kHz.
(4) Ultrasonic
Sounds inaudible to humans, above 20 kHz.
(5) Pollution and vibration
Vibrations that cause damage to human health and the living environment, which are generated by business activities, etc.
Generally, 1 to 80 Hz is considered the target.
(6) Seismic Activity
Ground vibrations (below 10 Hz) caused by the arrival of seismic waves.
(7) Guidelines for Evaluation of Habitation Performance
Technical data on building vibration presented by the Architectural Institute of Japan.
Traffic in the figure is vertical and horizontal vibration caused by road and track traffic (rail).
Wind indicates horizontal oscillations caused by strong winds.