Noise damage is painless, cumulative, and permanent
The threshold
Eighty-five decibels for eight hours, and every three decibels above halves the safe time. A circular saw is about a hundred, which is fifteen minutes.
What to use
Defenders or plugs, either is fine, and the one you will actually wear is the right one. Hanging them on the tool rather than a hook doubles use.
Tinnitus
Ringing after a task means damage has occurred. It usually fades and the damage does not, and it is the only warning the system gives.
