The Audio Forum plays rough sometimes, so take that with a grain of salt. There's lots of good info here, but it can get obscured by harshness of presentation. To everyone else, please remember that we have all levels of content creators here, from seasoned pros to no-budget hobbyists. It's easy to get trapped in our own perspectives, but it's also less than helpful to browbeat someone repeatedly.
Here's the deal, tbuelna:
1) There can be many causes of noise. Simply asking if folks who own the same devices have ever had issues with them is a pretty broad question that will invariably warrant a "yes" from some one. We have to know everything: the signal chain, what cables where used and in what sequence, whether the device was battery powered or using the AC adapter, etc. The more detail we have, the better-equipped we'll be to answer.
2) Please post a sample of the audio with the high-pitched noise. The easiest way to try and diagnose a sound problem is to hear it. No sound, no guess.
3) On-camera is the last and worst place to put a microphone. I can see, though, how you would not have heard the artifacts from the broken suspension during production, since there's no headphone monitoring from the camera. (I assume the VideoMic was plugged into the camera?) That aside, you really should not put any stock into on-camera mic audio. Use it for reference, but not for the mix.
4) When you are working on hobby-level shorts and relying on inexperienced crew, it's very helpful to sit down with those folks before hand and walk them through the kinds of things they need to monitor. For sound, that would include whistles, wheezes, and whines along with planes and phones and air conditioners and barking dogs. When you trust someone inexperienced with your sound, a little prep-work and training on the front end can help immeasurably during production.
