Ok, we just tested the devices here and everything plays very clearly with a pitch black noisefloor. We've texted, called, and emailed to and from the phone that was playing music and did not hear any interference. So now, it may get down to the cell frequency. Please report your cell provider and I will try to figure out which frequencies your phone is running at. We are on AT&T around here and it's possible that it's less prone to interference than your phone carrier. The other thought is signal strength. How many bars of signal do you have when you hear interference?