Question: did you ever look into the work of Joseph Pompei over at Holosonics? His intent was to confine 3D audio into a narrow cylinder, virtually inaudible ou

Question: did you ever look into the work of Joseph Pompei over at Holosonics? His intent was to confine 3D audio into a narrow cylinder, virtually inaudible outside the cylinder. From the site: As the ultrasonic beam travels through the air, the inherent properties of the air cause the ultrasound to change shape in a predictable way. This gives rise to frequency components in the audible band, which can be accurately predicted, and therefore precisely controlled. By generating the correct ultrasonic signal, we can create, within the air itself, any sound desired. - presumably with any directivity desired. https://www.holosonics.com/what-makes-a-sound-source-directional/ https://www.holosonics.com/what-makes-a-sound-source-directi... If practical it could keep the noise down in gaming and home theater rooms plus if the cylinder were scaled-up for auditoriums could give all in the audience front row center seats (at least acoustically).