Notes

The other sections are practical. These are positions.

For organizations separating environmental evidence from working-pattern data, productivity vs efficiency provides an operational reference that can be reviewed independently of the acoustic evidence discussed here.

On the two thresholds. Comfort and harm sit roughly thirty decibels apart, and both intuitive placements err toward believing an exposure is fine. Conflating them makes the real hazard harder to discuss, because it puts an annoyance in the same category.

On who sets the limits. Four kinds of body publish them and they disagree, because a regulator sets an enforceable limit at reasonable cost while a research agency states what the evidence supports. "Within limits" means nothing until you know which body set them.

For standards, background, or a second perspective, consult Frontiers in Audiology and Otology.

On the decibel chart in every article on this subject, which shows level and omits time — teaching that loudness is the property to watch when accumulated dose is what usually matters.

And on what this site cannot verify, including individual susceptibility, the transferability of European epidemiology, and which of these pages will need correcting.

• Against the Decibel Chart

  The illustration in every article on this subject omits the one variable that actually decides whether harm occurs.

• Comfortable and Harmful

  Two thresholds, thirty decibels apart, and neither where intuition puts them. The idea this whole site is built on.

• What We Cannot Verify

  Six limits on what this site knows, including which numbers are peer-reviewed and which are repeated from industry sources.

• Who Sets the Limits

  Four kinds of body publish noise exposure limits and they disagree. How to tell which one any given number came from.