Well, I was thinking more it's really hard for any layperson so reach a specific level of dBA, especially for single-frequency tones where the perceived loudness is usually different from the actual loudness.

So even if you say "This 100 Hz tone should be played for 2 minutes at 61 dBA, which is regular human speech levels", being able to actually get close to 61 dBA for a 100 Hz tone in real life, for an untrained ear, sounds pretty difficult.