intermittent static noise in a MacBook Pro 2015

I have an intermittent static noise that suddenly started today in my MacBook Pro 2015. The software also seems wrong, with long delays on shut down and startup and a >100% cpu effort by soagent for about a minute on startup. Following suggestions from communities, I reset the SMC and the NVRAM - neither helps. I also tried the safe startup - doesn't help either.

Can anyone help. Apple - please get in gear and answer this question yourself!

Thanks very much.