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How Distance Reduces Sound: The Inverse Square Law

Sound spreads out as it travels, so it gets quieter with distance. For a point source in the open, the level drops about 6 dB every time you double your distance.

📏 Distance & Loudness

Key points

  1. Sound energy spreads over a larger area as it moves away from the source.
  2. For a point source, level falls about 6 dB per doubling of distance.
  3. So a 100 dB sound at 1 m is about 94 dB at 2 m and 88 dB at 4 m.
  4. Indoors, reflections reduce this effect; outdoors in the open it holds well.
  5. Moving back is one of the easiest ways to make a loud environment safer.

FAQ

How much quieter is a sound twice as far away?

About 6 dB quieter for a point source in the open — which is roughly a noticeable drop in loudness. Use the calculator above to try values.

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