I heard this sound sometimes when logging on servers in older versions, but I just had it happen on singleplayer. Basically, I'm not sure how to reproduce this, but very rarely when opening a world, you'll hear the 'minecart.base' sound. I'm really not sure how to reproduce it, but it did happen, so please don't mark as "Can't reproduce". Just try to maybe make a world then duplicate it, then play on the copy, then delete the copy and redo. That's what I did and eventually it happened.