can't upload sound file

So, I’ve been trying to upload two sound files to Audacity for a video thing I was making for my boyfriend. One, I wanted to add an echo. The other, I wanted to make a distorted version of itself and make sound super scary. I rendered them both of .m4a files through Movie Maker, but Audacity wouldn’t recognize them. It told me to convert it to a file it recognized, like .wav or .aiff. So I converted them both to .wav files, but still Audacity won’t recognize them. It said to use the Import Raw Data thing, but when I did that, all I got was a second and half of jumpscare-inducing static. Twice.

Two days now, I’ve been trying to work on a solution and I’m out of options and long out of time. So, please, if you could help me out it’d be appreciated.
I uploaded the two sounds files below. Please help.

Here’s first pass. I added Effect > Echo: 0.1, 0.5 > OK to both. On the second one, I also applied Effect > Distortion > Leveler. Settings attached.

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