Sensing Loudness
Loudness is how strong or intense a sound seems. It is related to the amplitude, or size, of the sound wave, and is commonly measured in decibels (dB).
Questions you may have include:
- What is loudness?
- How does it relate to amplitude?
- What are decibels?
Loudness and amplitude
A sound wave with a larger amplitude carries more energy and sounds louder, while a smaller amplitude sounds quieter. Loudness is a different property from pitch: a sound can be high or low at any volume.
The decibel scale
Loudness is measured in decibels. The decibel scale is logarithmic, which means each step represents a large change in sound energy — so a sound at a higher decibel level is far more intense than the numbers alone suggest.
Protecting your hearing
Loud sound can damage the inner ear. As a general guide, prolonged exposure to sound above roughly 85 decibels can harm hearing over time, so limiting exposure and keeping volumes moderate is wise.
Summary
Loudness is the perceived intensity of a sound, set by the wave’s amplitude and measured on the logarithmic decibel scale. It is separate from pitch, and because loud sound can damage hearing, limiting exposure — especially above about 85 decibels for long periods — protects it.