I have heard this type of sound on several phones that I have owned. My Nexus 4 hasn't been delivered yet, but I can confirm that my Galaxy Nexus has a noticeable (but not annoying) buzz on 2G (GPRS/EDGE) networks. In that particular case, it is actually slight interference from the cellular radio.
Also many phones have an intentional soft hiss from the earpiece that is called comfort noise.
There are a lot of potential causes for this noise.
Sent from my Nexus 7 using Tapatalk 2
Also many phones have an intentional soft hiss from the earpiece that is called comfort noise.
There are a lot of potential causes for this noise.
Sent from my Nexus 7 using Tapatalk 2