Sounds May Be Louder Than What You Hear
How loud something sounds to you is not the same as the actual intensity of that sound. Sound intensity is the amount of sound energy in a confined space. It is measured in decibels (dB). The decibel scale is logarithmic, which means that loudness is not directly proportional to sound intensity. Instead, the intensity of a sound grows very fast. This means that a sound at 20 dB is 10 times more intense than a sound at 10 dB. Also, the intensity of a sound at 100 dB is one billion times more powerful compared to a sound at 10 dB.
Two sounds that have equal intensity are not necessarily equally loud. Loudness refers to how you perceive audible sounds. A sound that seems loud in a quiet room might not be noticeable when you are on a street corner with heavy traffic, even though the sound intensity is the same. In general, to measure loudness, a sound must be increased by 10 dB to be perceived as twice as loud. For example, ten violins would sound only twice as loud as one violin.
The risk of damaging your hearing from noise increases with the sound intensity, not the loudness of the sound. If you need to raise your voice to be heard at an arm’s length, the noise level in the environment is likely above 85 dB in sound intensity and could damage your hearing over time.
