Mac keeps making a noise at me but I don't know why

[Mildredop]

Every so often, My MacBook Pro makes that little "error" honk noise. It can be at any time and I can't link it to any particular thing I'm doing.

It most often does it a few seconds after it wakes, but it has just done it about a minute into me watching a YouTube video.

Nothing pops up, nothing seems untoward. Is there a way of finding out why it's doing it?

 

[SuperCachetes]

Only time I have ever gotten that sound is a calendar reminder, like a birthday or something I've put into the Calendar app.

Have you popped out the notifications tab and looked at it lately? (Top right of your screen, in the menu bar)