Do you have plans to measure cable-induced noise on in-ear headphones? This phenomenon is often called "microphonics" in audiophile circles (though I suspect the term is being misused). I'm referring to the audible rumbling and thumping noises that occur when the headphone cable is being moved. It seems to me that it has something to do with the stiffness of the cable. It's particularly egregious on my pair of Etymotic ER4PTs, for example.