I asked about my story on another list and learned the device used was
   an Audio Spotlight and it cost about $3000, and the individual likely
   still has it sitting on a shelf somewhere.
   [1]https://www.holosonics.com/
   The Audio Spotlight PrivateSound™ technology creates a tight, narrow
   beam of sound that can be controlled with the same precision as light.
   Aim the speaker at your desired listening area to keep sound focused
   specifically to your listeners and quiet everywhere else.

References

   1. https://www.holosonics.com/