Originally Posted by Robz26
It happens too frequently when the tire is barely rotating to think something got caught inside.
I've been fortunate enough to experience the cowbell a couple of times.
Exactly like your audio, and only could be heard at very low speeds, e.g. approaching a stop. Both times were preceded by driving in a parking lot with some gravel/pebbles.
Do something approximating a brake bedding session and see if it goes away. (With the regular brakes, that is.) Multiple stops from ~60 mph. Warm the brakes up and stomp on them. Worked for me.