I'll have two of whatever it is that guy is having
I chuckled at first as well; then over time, the theories have revealed themselves, slowly, through comments made in other threads, and, in part, by other people.
One of the most logical arguments that I've read is that the birdhouses act as the part of resonators, with the frequency dependent on the size of the box and port (bird entrance hole).
I don't know ::shrugs::, and I do not know enough to say anything one way or the other.
One thing I do know, is that every time that I've brought up room treatments for my space, I meet up with the
my living room, and,
you owe me a bigger house before you even think in that direction; then you can do anything that you want in your listening room.
So around my house, sound treatments amount to a fat negative WAF rating.
She did make some wall-hanging tapestries, which I guided her to mount behind the couch on the backwall (my listening spot).