Jbl waterproof flip 4, buy a waterbottle mount for a bike and clamp it to a handle or some rail on seats or something. 80 quid and just take it home when done.
I use the above sometimes on my rib and you can hear it no problem behind the windshield.
If you are feeling flush you can put a pair on later if you want and still have the ability to use them at home.
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