What is a Decibel (dB)?
A decibel (dB) is a logarithmic unit used to express the intensity or loudness of a sound relative to a reference level. It quantifies sound pressure levels on a scale from 0 dB, the threshold of human hearing, to over 140 dB for sounds that cause pain. A 3 dB increase represents a doubling of sound intensity, while a 10 dB increase is perceived by the human ear as twice as loud. Normal conversation is approximately 60 dB, while power tools can reach 100 dB and jet engines 140 dB.
Safe threshold for Decibels (dB)
Prolonged exposure to sounds over 85 dB can cause gradual hearing damage by harming the delicate sensory hair cells in the inner ear that transmit sound information to the brain.
The higher the decibel level, the shorter the duration of safe exposure before hearing protection is recommended. For every 3 dB increase in volume, the permissible exposure time before possible damage is cut in half. Decibels provide an objective way to quantify noise levels for regulating occupational and recreational sound exposures. Many countries have limits of 85-90 dB for an 8 hour workday. Measuring tools like sound level meters and noise dosimeters can help monitor decibel levels. Keeping decibel exposure as low as possible helps prevent noise-induced hearing loss over time.