Ultrasound Audio Spotlight can be only heard inside your head

Dr. Bruce Denardo explains how a audio spotlight works and gives a jaw-dropping demonstration.

The Audio spotlight is uses a set of transducers to generate a 65 kHz beam and because the wavelength of this beam is so small, it does not spread. In one sense, the audio spotlight is similar to a laser.

How do we make this 65 khz beam of acoustic energy audible, so you can hear something when the acoustic spotlight is pointed at you?

Scientists use ultrasonic mind control on monkeys
https://www.upi.com/Science_News/2020/05/20/Scientists-use-ultrasonic-mind-control-on-monkeys/3051589997922/