I love this stuff for quieting things down because it is non-adhesive but its expensive. I found a cheaper alternative that seems to be working just as well.
https://www.amazon.com/gp/product/B00MYDLRCQ/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B00MYDLRCQ/ref=oh_aui_search_detailpage?ie=UTF8&psc=1