What is the approximate change in sound level (in dB) when you triple the distance from the source?

When considering how sound levels change with distance, it’s important to understand the inverse square law, which states that sound intensity decreases with the square of the distance from the source. When you triple the distance from a sound source, the intensity of sound decreases significantly.

To quantify this change, for every doubling of distance, there is a decrease of approximately 6 dB. Tripling the distance can be thought of as a doubling followed by an additional increase in distance. The first doubling reduces the sound level by 6 dB. However, because tripling the distance does not represent a perfect doubling, one can consider the extra distance contributes less than another full 6 dB.

Considering these factors, when assessing the decrease in sound level when tripling the distance, the approximate overall change would be around 9 to 10 dB. Therefore, rounding to standard dB changes, the closest and most appropriate option is -10 dB.

This understanding of sound propagation is crucial for those involved in audio design, acoustics, or any field dealing with sound as it helps inform decisions about speaker placement, room design, and sound system setup to achieve desired auditory experiences.