Quantity   Component name
1 × Raspberry pi 1 model B
2 × NRF24L01+ modules Available from sparkfun, banggood, eBay, etc
1 × Arduino pro mini You could also use an arduino UNO, mega, or another micro controller of your choice. Just remember that the NRF24L01+ requires a 3.3V supply.
1 × analog sensor of your choice we made sensors from conductive wool, however you could use a potentiometer, a light sensor, etc. for examples see the links.
1 × external USB sound card compatible with rasperry pi we used a GWC Technologies AA1570 USB soundbox. For a list of compatible cards see the links.
1 × amp and speakers so that you can hear the sound! Any computer speakers will do.