If you take the corner of a piece of paper and place it in and align it with the grooves in the vinyl it becomes a speaker.
Discussion
Wow. Will try that with the kids! Trying to re-analogue them after my youngest called an LP a “Big Google”.
A nice crisp A4 sheet is best. The crisper the corner is the better and it's a bit of a balancing act to apply enough pressure to stay in the groove vs pushing too hard that the corner slips