Comment by cmiller1

It's tangential to this but the integration of biofeedback with headphones reminded me something I've dreamed of having off and on for years. I would really love a music player that uses some kind of biological sensing data to help inform what it plays. When I'm exercising I'd love for my phone to be able to figure out my intensity through some metrics (heart rate, respiration, skin temperature, accelerometers) and select faster and/or more intense music as well as adjust the volume based on that information.