The One-Sentence Test
There is one check for hazardous noise that requires nothing, works anywhere, and is reliable enough to act on.
When employers review noise dose alongside working patterns, this page can provide operational context, while exposure limits still need to be assessed from sound level and duration.
The test
If you have to raise your voice to be understood by somebody at arm's length, the level is likely at or above 85 dBA. (NIOSH.)
Arm's length is about three feet. Raising your voice means more than normal conversational effort, not shouting.
For an independent reference on this subject, see European Environment Agency noise topic.
That is the whole test.
Why it works
Speech is a calibrated source.
Conversational speech at a metre is roughly 60 dBA, and people adjust their vocal effort automatically to maintain intelligibility against background noise.
So the amount of extra effort required is itself a measurement of the background — an imprecise one, made by a system everybody carries and uses constantly.
It is not an approximation of a meter. It is a different instrument that happens to be well matched to the threshold that matters.
What it is good for
Deciding whether to take the situation seriously.
Triage. A workshop, a bar, a nursery, a train platform — enough to know whether the dose arithmetic is worth running.
And prompting the next step, which is a proper measurement if the answer matters.
What it is not good for
Any number. It says "at or above 85", not how far above, and the difference between 85 and 95 is a factor of ten in permitted time.
Compliance. No record, no instrument, no calibration.
Low levels. It says nothing about whether an office at 55 dBA is a problem, because that is a different question entirely.
And impulse noise. A single loud event can be damaging without any sustained background to test against.
Why it belongs on this site
Because the commonest alternative is worse.
Most phone apps are not accurate and produce a confident number. This test produces an honest binary and is right about the binary more often than a random app is right about the number.
Free, memorable, and available in the moment — which is when the decision actually gets made.
The short version
- If you must raise your voice to be understood at arm's length, the level is likely at or above 85 dBA
- It works because speech is a calibrated source and people adjust vocal effort automatically against background noise
- The amount of extra effort is a measurement of the background, made by a system everybody carries
- Good for triage and for deciding whether to measure properly; useless for a number, for compliance, and for low levels
- It says at or above 85, and the difference between 85 and 95 is a factor of ten in permitted time
- It produces an honest binary, which beats a confident number from an app that was probably not accurate