We often use decibels, a measure of sound pressure, to describe how loud something is - but loudness is caused by how we perceive sounds, and the two often don't line up.<br /><br />LEARN MORE<br />************<br />To learn more about this topic, start your googling with these keywords: <br />- Decibels (dB): a unit used to measure changes in pressure or power.<br />- Loudness: the intensity with which a sound is perceived.<br />- Weighted decibels (dBA): decibels that try to take into account our sensitivity for different frequencies to better approximate loudness.<br />- Frequency: the rate at which something occurs. In the context of sound, it usually means 'sound waves per second.<br />- Audible: perceptible for the human ear.<br />- High sound: a sound that has a high (fast) frequency<br />- Low sound: a sound that has a low (slow) frequency<br />- Resonance: When multiple things have a similar frequency they will tend to move together and amplify each other.<br />- Echolocation: Using sound to "see". Bats use this to hunt in the dark.<br />- Equal loudness contours: Curves that show the sensitivity of the human ear along the frequency spectrum.
