Audio shaking when playhead hits certains video clips?

First time user and have an issue and would appreciate any feedback. I have my edits loosely layed out but when the playhead hits certain video clips (or still shots) - the audio portion of my soundtrack starts 'shaking and breaking up' during that portion of the video. I've tried copying and pasting a new picture or video clip and same thing happens with the audio portion. can anyone shed some light on this for me in terms of how I can 'smooth' out the video portion? I'm basically ready to start tightening up my edits but am concerned about how the final version will sound. thanks so much! John Lawson

As a follow up to my post above...have determined that the issue with the audio breaking up appears to be when the playhead is at the point with the Video portion has approached a JPEG clip. In this case, I have two JPEGS back to back with an effect between the two. The audio portion underneath is fine with MP4s...this problem in the timeline is when it hits the JPEG clips. THATS when the Audio starts breaking up. I'm in the process now of reviewing a number of UTube videos in search of a solution. So far, nothing that works. I would really appreciate any feedback from anyone who has experience the same issue and has been able to resolve it...(see what I did there?)...sorry about that, anyway -- thanks in advance for any helping words! John...

Have you tried Caching?

It might help if you can post an example of what you mean, but it sounds like it's playing back slower than realtime because it's taking a long time to process each frame.

If your clips are very high resolution or you're using a lot of "difficult" effects (fades are easy, blurs and particle effects are very hard and take a long time to calculate) then you'll get this.

What's the spec of the machine you're running it on?