What is a distinguishing auditory characteristic sometimes reported during a momentary daytime blackout?

Answer

A sharp sound, perhaps like a switch being flipped off

Reports of momentary eclipses sometimes include an unnatural, sharp auditory cue associated with the visual event, described as a click or a switch being flipped off.

What is a distinguishing auditory characteristic sometimes reported during a momentary daytime blackout?
Darknessweatherskyatmospherephenomenon