If it's quiet (when the power is out) one may hear the slow surf-like sound of clothing brushing against itself. Not so much these last few nights, as the treefrogs have been going nuts.
The particular exercise that produces the surf-like sound is "wave your arms like a windmill that Don Quixote would tilt at" which isn't exactly traditional tai chi but we do our best. Also you'll need to wear something like a sweatshirt, and be in a quiet location.