OEMS Occupational Exposure Management Systems LLC

Sound Level Change with Distance

Assumes a point source in a free field, which drops about 6 dB per doubling of distance. Indoors, reflections usually make the drop smaller.

Solving for

–

Equation used

Variables

SPL₁ = level at distance d₁ (dB); SPL₂ = level at distance d₂ (dB); d₁ and d₂ in the same units

Source

CIH exam equation sheet