Cleaning unlear sound dstortion

[LO1]

I recorded two eulogies yesterday for the families concerned and had my Zen MP3 player (recorder) on the roof of the car near the speaker that was connected to the small amp in teh hearse.

 

Either the player/recorder was too near the speaker on the roof or the people who was talking into the microphone held it too close. The result is that I have distortion of sound and not a clean recording, is there any way to clean up this distortion. Many Thanks