MacBook Pro (late 2017) beeps twice, mechanical and loud, during regular use - passed diagnostics

This afternoon I was listening to music on Spotify (playing directly from the built in speakers from the client) when my computer very suddenly made a loud mechanical beeping noise twice consecutively which scared that daylights out of me. Obviously this isn't a sound you want to hear coming from any modern Macintosh. According to my roommate, it did this once more (two consecutive beeps) while I was out of the room. There have been no more unusual sounds since the first incident.

Concerned something was failing, I ran diagnostics after rebooting. She passed all diagnostic tests leaving me with no answers as to why the beeping occurred.

Should I be concerned something is wrong with my MacBook? This is the first time this has happened. I haven't heard sounds like this from a Macintosh since I was at least seven. As far as I know this was not a local emergency alert sound.

(ALSO - I did replay the song twice to make sure the beeping wasn't a part of the song I was hearing, but the song played back as usual.)