OT Distortion clipping? Not hitting 0.

[Dizzi45Z]

Okay, so my brother sent me a microphone recording that was done with his macbook. His microphone was turned up too loud during the recording of a presentation and it sounds like it is clipping, but when you look at the wave forms, they are no plateaus or times when the audio hits 0.

I decided I would try to clean up the distortion any way with izotope RX's declipper, but there seemed to be no improvement whatsoever.

What is exactly happening here in this type of situation? Is the microphone/macbook preamp overloading?

Any tools that can clean this sort of thing up?

Here is an image of what the wave file looks like.

Here is a link to download a clip of the audio:

[Craig F]

w/o listening, the mic or the mic pre could of clipped w/o clipping the converter
I'll listen later