If you think headphones are your only option on an ATV or a tractor, you need to check out what Boss can do for you. This Boss ATV25B portable sound system with marine-grade speakers uses heavy-duty Velcro straps to tie down to an ATV rack or a tractor roll bar, so it's easy to switch from vehicle to vehicle. You can power the ATV25B via your 12-volt cigarette lighter or use the included adapter for a more permanent wiring directly to your vehicle's battery.
The system's waterproof 6-1/2" speakers are built tough, and the system's marine-grade construction means you can even bring your boat into the rotation. Mud this Boss up, let it catch some sea spray, it won't matter.
Pair your media device via Bluetooth (or plug into the 3.5mm headphone jack), and you'll have inline up/down/play/pause controls to navigate your music. You'll control the volume through your media device, but the Boss ATV25B's internal amp gives you the power to shake the leaves off the trees if you've got a particularly loud engine to drown out. Polypropylene woofers and directional silk dome tweeters ensure that you'll get musical detail in all that volume.