Is the office in a big office building? Maybe a secretary upstairs was playing her radio too loud while the boss was away? Possible other solution.

Being someone who has autidory hallucinations, I say make a note of this in your mood tracker or whatever you do to keep notes. And, just kind of be alert. Stress and random noises, or other things can sometimes appear to be hallucinations. But, I always make a note. So if it happens again I can start to track a pattern. It's also good to do reality checking, so good to post about it like this.

It's like with diabetes, one really high blood glucose or one low one isn't necessarily an issue. It's looking for a pattern.