Help! How to clean up a digital interview recording (extreme static)

Factual Questions
1

I need to transcribe an interview recorded with an Olympus WS-311M digital voice recorder - verbatim. The problem is, the recording is of extremely poor quality for some mysterious reason - there’s a loud, buzzing static over the voices that almost drowns the interview, at least when played with a VCL Mediaplayer on my computer. Fiddling with the sound effect sliders doesn’t help, nor does using headphones. Of the fifteen-minute interview, I managed to transcribe maybe one fifth in bits and pieces in a good half-hour of sweaty concentration. The rest is basically inaudible in the present state / with the present equipment.

Is there any easy way to get rid of the static (and perhaps enhance the human voices) to make the recording intelligible? What might cause this in a quiet city apartment, the recorder sitting on an empty table between three people?

2

I have had good luck using Adobe Audition’s Adaptive Noise Reduction filter. It has automagically removed hiss from old recordings and ambient room noise from new ones that used a condenser mic. Your situation sounds a little more severe than that, but it never hurts to try it out.

3

Any of the software for cleaning static from record albums would help. I use Groove Mechanic, but that costs money (although you can test it on up to the first two minutes of a recording). Audacity includes noise reduction capability, and that is free. I didn’t like it as much for music when I was doing that, so I can’t say how well it works. But like I said, it’s free.

4

Electric or magnetic interference being picked up by the recorder, or air flow over the microphone are both possible.

5

I use Goldwave for sound editing, although I’m sure Audacity has the same capabilities.

In Goldwave, it is possible to sample a short section where the noise is by itself, then use that as a filter. I’ve found it works well as long as the noise is continuously in the background.

You might also try a gate. Our ears tend to ignore noise if other sounds are present. If carefully set, a gate can reduce the bad spots to nothing without touching other parts. This tends to create a very artificial on 'n off sound, so sometimes I add a little noise back in to make it sound more natural. It depends on your final requirements.

All electronics has inherent thermal noise and cheap electronics picks up noise from a number of sources. If the level was set very low, the desired sounds are no louder than the inherent noise.