Decibel Definition

What is a decibel?

The decibel is a relative unit of measurement corresponding to one tenth of a bel. It is used to express the ratio of one value of a power or root-power quantity to another, on a logarithmic scale. A logarithmic quantity in decibels is called a level.

Sound travels in waves. The intensity of energy that these sound waves produce is measured in units called decibels (dB). The lowest hearing decibel level is 0 dB, which indicates nearly total silence and is the softest sound that the human ear can hear. Generally speaking, the louder the sound, the higher the decibel number.

    Sound Frequency

    Noise measurement of common sounds:

    • Whisper: 30 dB
    • Normal conversation: 60 dB
    • Lawn mower: 90 dB
    • Movie theater: 80-100 dB
    • Live music: 100-115 dB

    When it comes to damaging levels of sound, the magic number is 85. Researchers have discovered that extended or repeated noise exposure to levels of 85 decibels or above can cause permanent hearing loss.

    Three main factors influence the severity of hearing damage:

    • Sound level (how loud the sound is)
    • Proximity (how close you are to the sound)
    • Time (how long you are exposed to it)