TEControl shared this video, featuring film and TV composer Dan Radlauer demonstrating how he uses their USB MIDI Breath and Bite Controller 2 (BBC 2) to play virtual instruments more expressively.

The BBC 2 captures four independent MIDI streams, for four types of expression:

A piezoelectric transducer senses breath pressure

The bite sensor senses the the force applied to the mouthpiece by teeth or lips

The integrated accelerometer senses head nod and tilt

Details on the BBC 2 are available at the TEControl site.