OK I bought some water resistant bone conduction earphones

They work perfectly and hook to my ears so they can’t fall off!

Update: you are correct, the water-resistant bone conduction set works like a charm. And they won’t fall off. I’d say your solution is conservatively .5% what I would have paid for the less satisfying parametric array.

You correct. But I’m clumsy and interrupt-driven. I would somehow forget about them, drop them on the floor, then trip on them and break a hip.