Xfinity camera buzzing sound when video is played back

When playing back video, my Xfinity camera keeps making a buzzing sound like the sound has been disabled by someone interfering with my camera.  I saw my neighbor walking across my deck the other day for no reason and am wondering if they somehow hacked my camera.  Can Xfinity tell if my camera has been hacked or if someone is using some type of device to interrupt my camera.  This is a serious matter.