Decibel (dB)
A logarithmic unit used for sound levels and hearing-test thresholds.
A decibel value needs context such as frequency weighting, measurement method, distance and duration. NIOSH’s 85 dBA reference is an occupational eight-hour time-weighted average, not a universal personal safe-time threshold.
Primary reference: CDC/NIOSH noise-limit explanation. This definition is general information, not an individual assessment.
Read more: Occupational noise-dose reference