LG V VX-9800

I have had my V for over 2 weeks now, and am becoming more and more aware of a strange "swishing" sound coming through the speakers of my phone, (or even through a headset), whenever I start to use my phone. I don't quite know how to describe it, but the sound doesn't happen all the time. If it does, the swishing sound disspears pretty quickly if and when it does happen. It seems that my phone functions perfectly, but I'm kind of annoyed. I just want to know if anyone has noticed this sound with their phones, or should I be concerned?

Thanks.