Ian Gordon, a 50 year old male from Exeter UK asks on December 29, 2005,Why are sounds so much louder downwind, even when the wind is light?
viewed 14854 times
Sound waves are pressure waves. They are relatively tiny variations in air pressure, too small to be felt as wind, but they are carried through the air around us. Sounds are louder downwind due to something called downward refraction which happens because air on the ground moves slower than air higher up. There is a steady increase in wind speed as you get higher off the ground. This acts on sound in the same way a prism acts on light. It tends to bend sound downward. The sounds hit the ground and bounce off, so you end up with multiple copies of the same sound and it sounds louder to your ears.
Note: All submissions are moderated prior to posting.
If you found this answer useful, please consider making a small donation to science.ca.