Thanks for reaching out @amylm1, I hope you're well today!
Can you try opening the file on your laptop in another media player app, to see if the sound is also distorted there?
If so, please try downloading the file again via an incognito browsing window, or even another web browser to see if there's any difference there.
Also, when you preview the file in your Dropbox account online, does it play fine from there?
Keep me posted!