How we source the numbers
Every level on this site comes from a published measurement, standard or record, and every one links to it. 154 sounds, 224 distinct sources.
The rules
- Every number has a citation: government and standards bodies (CDC/NIOSH, OSHA, HSE, the EU, WHO), peer-reviewed papers, manufacturer specifications, Guinness World Records for records, and measurement reports.
- We record what was measured: A-weighted (dBA), C-weighted (dBC) or unweighted; an average, a maximum or an instantaneous peak; and the distance or position. Peaks from gunshots and fireworks are not dBA and are not shown as dBA.
- Where sources disagree we show the range rather than picking one.
- Each source entry includes a short verbatim quote containing the figure. A script re-fetches every source and checks the quote is still on the page; the date it was last checked is shown beside it.
- If a sound could not be cited, it is not on the site.
Safe exposure times
The “safe” times use the NIOSH recommended exposure limit: 85 dBA for 8 hours, halving for every 3 dB more. OSHA’s legal limit and the UK and EU action values are shown alongside on each page. These are occupational limits designed for working adults; they are not a promise that shorter exposure is harmless, and they were not designed for children.
The Scroll
Sounds sit at the midpoint of their measured range. The spacing between them is proportional to the difference in decibels, compressed where many sounds cluster and capped across the longest empty stretches. The waveform down the middle widens on a logarithmic scale; drawn to true pressure, everything quieter than a jet engine would be thinner than a hair.
Sound samples
Samples are public domain or CC0 only, cut to a few seconds and normalised to the same loudness (−24 LUFS), then played through a fixed gain cap. 25 samples: NPS Sound Gallery: Rain (nri-RainDEPO.mp3) (National Park Service (Credit / Author: NPS), Public domain (US government work, National Park Service)); NPS Sound Gallery: Crickets (nri-Cricket.mp3) (National Park Service (Credit / Author: NPS), Public domain (US government work, National Park Service)); NPS Sound Gallery: Thunder (nri-Thunder.mp3) (National Park Service (Credit / Author: NPS), Public domain (US government work, National Park Service)); NPS Sound Gallery: Ocean (nri-OceanOlympicNP.mp3) (National Park Service (Credit / Author: NPS), Public domain (US government work, National Park Service)); NPS Sound Gallery: Hermit Thrush (nri-HermitThrushYOSE.mp3) (National Park Service (Credit / Author: NPS), Public domain (US government work, National Park Service)); NPS Sound Gallery: Motorcycle (nri-MotorcycleMORA.mp3) (National Park Service (Credit / Author: NPS), Public domain (US government work, National Park Service)); NPS Sound Gallery: Helicopter (nri-HelicopterYOSE.mp3) (National Park Service (Credit / Author: NPS), Public domain (US government work, National Park Service)); NPS Sound Gallery: Jet (nri-JetYOSE.mp3) (National Park Service (Credit / Author: NPS), Public domain (US government work, National Park Service)); NPS Sound Gallery: Chainsaw (nri-ChainsawSEKI.mp3) (National Park Service (Credit / Author: NPS), Public domain (US government work, National Park Service)); NPS Sound Gallery: Humpback Whale (nri-HumpbackGLBA.mp3) (National Park Service (Credit / Author: NPS), Public domain (US government work, National Park Service)); Cicada orni.ogg (DavidDelon, Public domain (PD-self)); Medium rooster crowing.ogg (alys, Public domain (PD-author, PD-pdsounds.org)); Baby long wanting cry.ogg (natalie, Public domain (PD-author, PD-pdsounds.org)); Snoring of old man.ogg (Saaabaaato, CC0 1.0); Sunday in the city street noise1.ogg (cori, Public domain (PD-author, PD-pdsounds.org)); AirChime K5LA.ogg (HarveyHenkelmann, CC0 1.0); American police siren i.ogg (lezer, Public domain (PD-author, PD-pdsounds.org)); Lawnmover diesel.ogg (stephan, Public domain (PD-author, PD-pdsounds.org)); Pneumatic drill - The Cleveland Pneumatic Tool Company.ogg (ldezem, CC0 1.0); Fireworks piece.ogg (stephan, Public domain (PD-author, PD-pdsounds.org)); The Mist Covered Mountains - Pipe Band - United States Air Force Reserve Band.mp3 (Composition: traditional; Performance: United States Air Force Reserve Pipe Band; Recording: United States Air Force Reserve Band, Public domain (PD-USGov-Military-Air Force)); Sperm Whale Normal Clicks.ogg (National Oceanic and Atmospheric Administration, Public domain (PD-USGov-NOAA)); Discovery STS-131 — Sound of Launch.mp3 (NASA, Public domain (PD-USGov-NASA)); Apollo 14 Launch.webm (NASA, Public domain (PD-USGov-NASA)); Blue Whale NE Pacific, speed 10x (nepblue24s10x.wav) (NOAA Pacific Marine Environmental Laboratory (PMEL) Acoustics Program, Public domain (US government work, NOAA PMEL)).
Corrections
Spotted a number that does not match its source, or a better source? Email hello@hushtoboom.com.
Not medical advice
This site explains sound levels and published limits. It cannot assess your hearing. If you notice ringing, muffled hearing or a change in your hearing, see an audiologist or your doctor.