The Neurophone is an invention that allows you to transfer sound directly into the brain using either radio signals, or ultrasound. A DIY version of the latter was developed by Andreas using a simple PWM modulator IC TL494 and piezoelectric speakers.
The second version of the “Neurophone” used ultrasound instead. By modulating an ultrasonic signal with the audio we want to listen to, it gets picked up by a little-known part of the brain and turned into something that feels like sound.
The weird thing is this works even if the ultrasound transducers are far away from the head: maybe down at your waist, or even further (depending on your body).
Via Hacked Gadgets.