buzz

Very obvious buzzing in the last clip before memory runs out: http://myaccount.dropsend.com/file/27515d89cc3cb0c0 For other clips it's slight softer, is this normal? Earlier, not important: http://myaccount.dropsend.com/file/d2e73a1d4ca6b8a4

Recently purchased the SGZC12SS and have been using it for several days. I've posted some raw footage below so you can see/hear what I'm attempting to discuss (The file is a part of the entire 5min raw video that was recorded) There is a distinct buzz from the start of the video to the end, as...