While using my notebook, I thought I saw some sort of weird spark by the right side near the USB port. Then briefly smelled something burnt.

Decided to shut down and check if there was anything amiss.

After rebooting it, I noticed that the sound was not working right.

The sound seemed muffled, like someone was covering the speaker somehow. But there is no apparent issue with the speaker on the outside. Software settings haven't changed as far as I could tell.

Anyone have any idea what might be the cause? Or what is happening?