Safe Listening Time Calculator
How long is a given sound level safe before it starts to damage your hearing? This calculator uses the NIOSH and OSHA workplace exposure formulas to give a real answer for any level from 70 to 130 dB.
Regular exposure to loud environments (concerts, workshops, industrial workplaces, high-volume headphone listening) causes progressive high-frequency hearing loss. The damage shows up first as difficulty catching consonants in noisy places. Spy Hearing has an 8-band parametric EQ that can boost the frequencies you are starting to lose, plus up to 16x amplification for hearing quiet audio on iPhone.
Try Spy Hearing on iPhoneWhat the calculator is based on
Two workplace noise exposure standards, both derived from decades of hearing-damage research:
NIOSH (recommended)
The National Institute for Occupational Safety and Health uses an 85 dB reference for 8 hours and a 3 dB exchange rate. Every 3 dB doubles the acoustic energy, so every 3 dB halves the safe exposure time. This is the more health-protective standard and matches the underlying physics of hair-cell damage in the cochlea.
OSHA (legally required in the US)
The Occupational Safety and Health Administration uses a 90 dB reference for 8 hours and a 5 dB exchange rate. OSHA is what US employers are legally required to comply with, but the standard is older and less strict than what modern hearing research supports. NIOSH is what hearing scientists actually recommend.
Safe listening time reference
| Sound level | NIOSH safe time | OSHA safe time | Example |
|---|---|---|---|
| 75 dB | 25 hours | 32 hours | Vacuum cleaner, busy restaurant |
| 80 dB | 8 hours (borderline) | 16 hours | Alarm clock, city traffic |
| 85 dB | 8 hours | 16 hours | Heavy traffic inside car, gas mower |
| 88 dB | 4 hours | 10.6 hours | Motorcycle passing at 25 ft |
| 91 dB | 2 hours | 7 hours | Subway train, hair dryer |
| 94 dB | 1 hour | 4.6 hours | Blender, food processor |
| 97 dB | 30 minutes | 3 hours | Power lawnmower |
| 100 dB | 15 minutes | 2 hours | Motorcycle, hand drill |
| 103 dB | 7.5 minutes | 1.3 hours | Nightclub, snowmobile |
| 106 dB | 3.75 minutes | 52 minutes | Chainsaw, jackhammer |
| 109 dB | 1.9 minutes | 34 minutes | Live rock concert |
| 112 dB | 56 seconds | 23 minutes | Ambulance siren at 10 ft |
| 115 dB | 28 seconds | 15 minutes | Loud rock concert front row |
| 120 dB | Under 9 seconds | 7.5 minutes | Jet takeoff at 100 ft |
| 125+ dB | No safe exposure | No safe exposure | Immediate risk, pain threshold |
Numbers assume a full recovery period after exposure (roughly 16 hours of relative quiet). Consecutive loud days accumulate damage even if each individual day looks within limits.
How the formula works
NIOSH safe daily exposure time in minutes: T = 480 / 2^((L - 85) / 3) where L is the sound level in dBA. OSHA uses T = 480 / 2^((L - 90) / 5). Both take a reference level (85 or 90 dB) that is safe for 8 hours (480 minutes) and apply an exchange rate that halves the safe time for each 3 dB (NIOSH) or 5 dB (OSHA) increase.
The exchange rate matters. A 3 dB increase doubles the acoustic energy hitting your cochlea. NIOSH's 3 dB rate matches that physics. OSHA's 5 dB rate is more forgiving because it was established when hearing protection was less advanced and stricter limits felt impractical to enforce. Modern audiology consensus is that NIOSH is closer to the biological reality.
What to do if your daily exposure exceeds the safe limit
- Reduce exposure time. The simplest option. Cut the loud activity in half and the risk drops accordingly.
- Use hearing protection. Foam earplugs reduce sound by 20 to 30 dB (NRR rating on the packaging). At a 90 dB workplace, that brings effective exposure down to around 65 dB, which is unrestricted.
- Move further from the source. Sound falls off by 6 dB for every doubling of distance. If you can double your distance from a loud machine, you cut its exposure in half.
- Try active hearing protection. Modern electronic earmuffs (Peltor, Walker's, Howard Leight Impact) let normal-volume speech through while cutting sudden loud noises. AirPods Pro 2 and Pro 3 have a similar Hearing Protection feature in iOS 18.1 or later.
- Get a real audiogram. If you have had years of noise exposure, a baseline audiogram from an audiologist tells you where you actually stand. Every audiology clinic offers this, often free through employer health plans.
Related tools on this site
Measure the actual sound level in a specific environment first with our Decibel Meter tool, then plug that number into this calculator. And check how young your ears are to see whether past noise exposure has already caught up with you.
Frequently asked questions
- How long can I safely listen at 85 dB?
- By NIOSH guidelines, 8 hours of exposure at 85 dBA is the daily safe limit. This is the exposure level where the risk of noise-induced hearing loss becomes measurable if repeated day after day. OSHA (older standard) allows 16 hours at 85 dB. NIOSH is the more health-protective standard and matches current audiology research.
- Is 90 dB safe for 8 hours?
- OSHA says yes, NIOSH says no. Per NIOSH, 90 dB is safe for about 2 hours per day, not 8. Per OSHA (US legal minimum), 90 dB is safe for a full 8-hour workday. NIOSH is the recommendation from actual hearing scientists; OSHA is the enforceable regulation, which is more permissive because it was set decades ago when enforcement of stricter limits felt impractical. If you care about your hearing, use NIOSH.
- What is the difference between NIOSH and OSHA exposure limits?
- Two things. First, the reference level: NIOSH uses 85 dB as the 8-hour safe limit, OSHA uses 90 dB. Second, the exchange rate: NIOSH halves the safe time every 3 dB increase, OSHA halves it every 5 dB. Every 3 dB doubles the actual acoustic energy hitting your ears, so NIOSH matches the physics. OSHA is older, less strict, and legally enforceable in US workplaces. NIOSH is what audiologists actually recommend.
- What is the loudest sound safe to hear without hearing protection?
- By NIOSH standards, any brief exposure above 115 dB carries meaningful damage risk, and continuous exposure above 100 dB should be limited to 15 minutes or less. Above 120 dB, no exposure is considered safe without protection. Even a single brief exposure to 140 dB or more (fireworks at close range, gunshots) can cause immediate permanent hearing damage.
- How loud is too loud for headphones?
- A rough test: if someone standing next to you can clearly hear what you are listening to, your headphones are above 85 dB and risk cumulative damage over years. Most phones let you set a volume limit in Settings (iPhone: Settings > Sounds & Haptics > Headphone Safety). Aim for below 60 percent volume with over-ear headphones or 50 percent with earbuds as a rough safe cap.
- Do earplugs actually work?
- Yes, if you use them correctly. Foam earplugs rated NRR 29 or 33 (printed on the packaging) reduce sound by roughly 20 to 30 dB when properly inserted, which is enough to bring most concert or workplace noise into a safe range. The real-world reduction is often lower than the rating because most people underinsert foam plugs. Roll the plug thin, pull the ear up and back, insert deep, hold for 30 seconds while the foam expands.
- Does noise damage accumulate over years?
- Yes. This is the core of noise-induced hearing loss. Each loud exposure damages a few hair cells in the cochlea, and hair cells do not regenerate. The damage shows up decades later as high-frequency hearing loss and often tinnitus. This is why NIOSH limits are set assuming daily lifetime exposure. A single loud concert probably will not hurt you; going to loud concerts every weekend for 20 years will.
- Where does the 85 dB reference come from?
- From longitudinal studies of industrial workers correlating exposure levels with audiogram-measured hearing loss decades later. NIOSH determined that 85 dB TWA (time-weighted average) over an 8-hour work day, repeated for a working lifetime, produces a measurable increase in hearing loss risk above baseline aging. Below 85 dB TWA, the noise-induced portion of hearing loss becomes negligible relative to normal presbycusis.