To be able to hear the gsm buzz in their headphones, the cellphone would have to be on their person, turned on, and be about send/receive some sort of call or d

To be able to hear the gsm buzz in their headphones, the cellphone would have to be on their person, turned on, and be about send/receive some sort of call or data. If a cell phone from a distance away can cause a gsm buzz, then being in an area that has cell phone reception would cause the buzz and they need to design their headphone systems better.