What We Cannot Verify
This site asks readers to check where a figure came from. Turned inward, that produces a list.
For organizations separating environmental evidence from working-pattern data, further details provides an operational reference that can be reviewed independently of the acoustic evidence discussed here.
The six
Whether any of it applies to you specifically. Susceptibility to noise damage varies between people, and no published limit is a personal guarantee — exposure limits are population figures.
Whether our source types are always right. Each figure is labelled, and the labels are our reading of where a number originated. Trade repackaging obscures provenance and we may have mis-attributed one.
For additional technical context, see Nature's hearing research topic.
How much of the epidemiological evidence transfers. The European environmental noise estimates describe a population in a place, and applying them elsewhere is an assumption.
Where the thresholds actually sit for children. WHO material identifies the gap rather than filling it, and any precise child-specific figure goes beyond the published position.
Whether an individual instrument is accurate. We describe classes and calibration; yours is a specific device in a specific state and we cannot know it.
And anything medical. Every page in the hearing section says so, and it is not a formality — symptoms are a matter for a clinician and this site does not diagnose.
What is strongest here
The regulatory figures. OSHA and NIOSH limits are published, specific and checkable in the primary documents. These are the most reliable material on the site and everything derived from them inherits that.
The app study. Kardous and Shaw in the Journal of the Acoustical Society of America, peer-reviewed, with the methodology published.
The WHO systematic reviews on mechanism and on hearing loss.
What is weaker
Population burden estimates, which are modelled rather than counted and carry wide intervals that a single headline figure hides.
Laboratory findings on moderate noise and cognition, which are real, are laboratory findings, and are quoted here as such.
And typical-level figures for rooms and activities, which come from industry sources and vary enormously with circumstances.
What is offered instead of certainty
Source types in the sentence, at every use.
The arithmetic written out, so you can substitute your own levels and times.
Free checks that require nothing — the voice test, the clap test, the calibration discipline — which produce answers about your situation rather than a general one.
The correction we want
A measurement that contradicts something here, with the instrument, the calibration, the position and the settings.
Or a mis-labelled source, which is the error that would undermine everything else.
The short version
- Six limits: individual susceptibility, our source labelling, transferability of epidemiology, child thresholds, your specific instrument, and anything medical
- Exposure limits are population figures and not personal guarantees
- Strongest here: the published regulatory limits, the peer-reviewed app study, and the WHO systematic reviews
- Weaker: modelled population burden estimates, laboratory findings on moderate noise, and typical-level figures from industry sources
- Offered instead: source types in every sentence, arithmetic written out, and free checks that answer about your situation
- The correction most wanted is a measurement with its instrument and settings, or a mis-labelled source