The shape of the yin and yang sections of the symbol, actually gives you a sense of the continual movement of these two energies, yin to yang and yang to yin, causing everything to happen: just as things expand and contract, and temperature changes from hot to cold.
Sound is measured in units called decibels. Sounds of less than 75 decibels, even after long exposure, are unlikely to cause hearing loss. However, long or repeated exposure to sounds at or above 85 decibels can cause hearing loss. The louder the sound, the shorter the amount of time it takes for NIHL to happen.
Decibels are in essence a measure of volume. The volume or intensity of sound is measured in units called decibels (dB), generally on a scale from zero to 140 (any higher than 140 and you are in trouble immediately). The higher the number in decibels, the louder the noise. The louder the noise, the greater the risk of hearing loss.