There's quite some research, and even some products (I mentored a company about five years ago doing such a thing, but I even forgot their name, and don't remem

There's quite some research, and even some products (I mentored a company about five years ago doing such a thing, but I even forgot their name, and don't remember what their outcome was) about this topic. - https://www.hindawi.com/journals/js/2018/4105208/ https://www.hindawi.com/journals/js/2018/4105208/ If memory serves, you don't even need to have permanently installed sensors, you can do it with a portable stethoscope kind of contraption which can detect anomalies and help to schedule preventative maintenance.