Quantity   Component name
2 × MPR121 capacitive touch sensor IC/breakout modules
3 × Arduinos- pro minis, nanos, etc Qty depends on your approach to dividing the tasks up but three should be enough
1 × Headphones Either in-ear or over the ear but make sure they will stay on the patient.
1 × DS1801+ logarithmic digital potentiometer for volume control
1 × Headphone socket To connect headphone jack to the volume control IC
1 × Copper foil tape To make capacitive plates on the insoles
1 × 2-3mm thick neoprene foam sheet To cover the foil plates on the insole
3 × NRF2401 etc radios To provide a wireless connection from the feet to the audio pack, which will generate the tones, control volume and interface with headphones.