Echo or Reverb? Not sure...please help

First time post for me, but I’ve used Audacity before for small projects always with good results.

However…

This project has me perplexed. I have a bunch of iPhone videos of a fishing trip I made to Canada with my brothers back in 2012. For some reason, these are the only video files I have in my vast collection that have this strange echo or reverb effect in them. My problem is that I can’t seem to get rid of it. In fact, I’m not really sure if it is echo or reverb at all, and maybe it’s a common problem that I have not diagnosed properly.

I’ve used iMovie to detach the audio track from one of the videos and uploaded here for review.

Does anyone know what this effect is and if it is possible to remove?

I don’t think that’s fixable. IMO it’s a digital artifact: short-stutter which sounds like echo/reverb.
If it’s not on the video, try software other than Audacity to rip the audio from the video.