Cleaning the air is good.

PC fan boxes are a quieter option too: https://itsairborne.com/pc-fan-corsi-rosenthal-guide-a611dab...

(Incidentally, PC fans can also be used to pull/push air through N95/FFP2 masks.)

* https://media.npr.org/assets/img/2021/08/25/corsi_box-design...

* https://media.npr.org/assets/img/2021/08/25/corsi_instructio...

* https://EdgeCollective.io/airbox

* https://reddit.com/r/crboxes