I've used bone conduction headphones for comms under ballistic helmets. Didn't care for them since the placement was very important to be in just the right spot, making it uncomfortable for long periods of time.
For a while I've been using wired ear buds connected to a phone for music and finally got around to getting a Bluetooth headset (review coming shortly) and it's world's better. I can put ear plugs and music as well.