If you apologize for something that actually wasn’t noticed: let it go or explain?

Recently at a church meeting online, I swore repeatedly (using the F word), although whispering, thinking that my microphone was off. Unfortunately my microphone was on. People at the meeting later told me that they could hear my mouse clicking, and so I tested everything and figured that if they heard my mouse clicking, they also heard me swearing.

I emailed everyone in the meeting and apologized for "unacceptable language" that I had used.

One person responded, "I your mouse clicking but didn't hear you say anything."

So now the situation maybe worse, since they don't know what I said, and they could think that I said something racist or sexist, which would be worse than a four letter word.

In a situation like this where you apologize for something, but what you did wrong actually wasn't noticed: explain further (so that everyone doesn't think that you did something worse than you did), or let it go?

Thanks.