CVR
For interest
There are pressure waves and structural borne waves, both longitudnal and lateral along the planes axis. The structure borne waves arrive the quickest and the decoding of these relative to any pressure waves is key to the location of the hammer blow etc.
Unfortunately or fortunately there is a data bank of previous CVRs to compare against, both for bombs and structural only failures.
I'm in the wait and see mode for what cards will be released in the news on this.