This 2015 course at a military academy presents another synthetic telepathy technology

This 2015 course at a military academy presents another synthetic telepathy technology, this one based on ultrasound.

The device projects a focused beam of ultrasound at 65 kHz, based on complex physical principles.
The sound is then audible only within the beam, and only as it approaches the target to which the device is directed.

Although little-known, this type of device has been available to the general public for many years; they are sold by the manufacturer Holosonic (https://www.holosonics.com/) and used by museums, exhibitions and advertising campaigns.

We have already detailed the offensive uses to which such technologies can be put in the context of classified mind-control projects.