I have been shifted to a video role at my publication and am using the 5D Mark II. Has anyone figured out a way to monitor the audio from the camera?

I know that BeachTek is developing an adaptor for release around April, but I need a quick fix in the meantime. I’m using a Sennhieser wireless system to capture the audio, but it doesn’t have a headphone jack. When I plug headphones into the A/V output on the camera I just get distortion. It could just be user error on my part, but if not I see this as a major flaw in the camera.

Any thoughts or help would be greatly appreciated.