Bell X-1 sonic boom.

I was watching a program on the Canadian Discovery Channel on the
American Rocket Program, in particular, when the Bell X-1 broke the "so
called" sound barrier in 1947. It stated that ground crews were startled by
the "first ever" sonic boom. The first ever perhaps, produced by a manned
aircraft, as sonic booms are generated by some meteoroids entering the
earth's atmosphere. I was wondering if the V2 rockets fired during WWII
produced an audible sonic boom on the ground. Not at the impact site of
course but prior to impact just as the Space Shuttle produces one on
re-entry? Perhaps the "boom" was not recognized as being produced by a V2!