One of the projects that caught our eye at NYU's ITP winter show last night (the program that brought you Big Screens) were the Head(banger)phones, accelerometer-equipped to change the music as you bob your head.
Lee-Sean Huang attached the accelerometer to the top of the headband, and fed its data readings into the visual audio programming platform Max/MSP to control the sound output based on where your head is at, so to speak. But unlike the horribly bad mushroom trip that you could not escape from after listening to Massive Attack, all it takes to change things up—in this case, shifting in and out between various synth samples to make a live mix—is to bob your head. It's not for switching tracks on your iPod, think of it as more of a crossfader that works not just in one dimension (left and right) but in 3D space, blending various elements of a track in real time.
Accelerometers are in everything, so adding them to consumer headphones would be the easy part. Coming up with a novel way to utilize the sensor readings to change the sound, now that's the trick. I told Lee-Sean he should hook up the guy from the Boredoms with a pair—I think he'd love them.