No sound in iMovie

That's strange. Try using Handbrake to convert your clips to Mp4/AAC even though they are already in that format. Sometimes a conversion clears up glitches. Then see if the sound will play in iMovie.

When you select the clip in the timeline and click on the little loudspeaker icon in the tool at the upper right of your screen, is the box checked that says "Lower volume of other clips"? If so, try unchecking it.

-- Rich

What operating system and iMovie version are you using? Have you updated to Catalina and current iMovie? Does the audio portion of the video clip show wave forms when in the timeline (Settings button above and to the right of the timeline/Show Waveforms). What format is the audio? iMovie likes AAC. You can check the format by opening the video in QuickTimePlayer and clicking on Window/Show Movie Inspector.

After displaying the wave forms confirm that the horizontal volume line has been pushed up to allow sound in the clip.

If all O.K. there, try opening iMovie while holding down the Option and Command keys and selecting to delete preferences in the box that appears. iMovie will open in a new library. Reopen your old library to get back to your projects. Now see if you get sound.

Also, possibly the issue is confined to just one project. To rule that out, create a new project and import your clip into it to see if you get sound.

You can also try using a video converter like Handbrake to convert the clip to Mp4/AAC that Handbrake will do by default. You can get Handbrake here:

https://handbrake.fr/

If nothing seems to be helping, you might try redownloading iMovie. To do that, drag your present iMovie app from the Applications folder to the trash, but don't empty the trash.

-- Rich

Great! Glad it worked for you. :)

-- Rich