Hi,
todays headline news contains a link
"Sound-Beam Inventor Wins $500,000 Lemelson-MIT
Award"
https://www.msnbc.msn.com/id/7536267, saying
that a lonesome guy invented the "sound-beam". But
Sennheiser
https://www.sennheiser.com/sennheiser/icm_eng.nsf/root/09859
already offers something like that since 2000, so
who was the first ? Or maybe both invented it at
the same time ?