Sounds don't always play

I was building something and noticed that sometimes when I placed and broke blocks, there was no sound.

What I expected to happen was that the sound would play as usual.

What actually happened was that sometimes, as far as I can tell, randomly, the sound didn't play.

Steps to reproduce:

1. Just try placing and breaking blocks. I was in creative mode at the time, but I don't know whether that has anything to do with it or not.

Also, I am sorry if this is a duplicate. I couldn't find a report of this when I searched.