Hearing Damage Risk Calculator
Estimate safe noise exposure time from sound level in decibels using NIOSH and OSHA guidelines. 85 dB safe for 8 hrs (NIOSH), 90 dB for 8 hrs (OSHA).
Noise-induced hearing loss is one of the most common occupational hazards and recreational risks worldwide.
NIOSH (National Institute for Occupational Safety and Health) recommends a maximum exposure of 85 decibels (dB) for 8 hours. For every 3 dB increase above 85 dB, the safe exposure time is cut in half.
Safe exposure time formula (NIOSH):
T = 8 / (2 ^ ((dB - 85) / 3)) hours
Common noise levels:
- Normal conversation: 60-70 dB (safe)
- Vacuum cleaner: 70 dB (safe)
- City traffic from inside car: 80-85 dB (8 hours max)
- Lawn mower: 90 dB (about 2.5 hours)
- Concert or nightclub: 100-110 dB (minutes only)
- Chainsaw: 110 dB (about 1.5 minutes)
- Fireworks at close range: 140-160 dB (immediate damage)
OSHA (Occupational Safety and Health Administration) uses a slightly more lenient standard with a 5 dB exchange rate. NIOSH uses a 3 dB exchange rate, which is considered more protective and is used in this calculator.
Hearing protection reduces effective noise exposure. Foam earplugs typically reduce noise by 20-30 dB. Over-ear muffs reduce noise by 25-35 dB. Using both together can provide 30-40 dB reduction.
Key facts:
- Hearing damage is cumulative and permanent.
- Ringing in the ears (tinnitus) after exposure is a warning sign.
- Regular hearing checks are recommended for anyone exposed to loud environments.