Skuba Water Resistant Bone Conduction Headphones

I had high hopes for this product, I really did. I had intended to use this on long motorcycle journeys where you really do have to put ear plugs in to stop the wind noise and bone conducting phones seemed to be an ideal solution solution to fend off...

I used them to swim, and the volume of the music is really really slow. On the box (but not in the amazon description!) they say that this may be a problem, and they can sell you an amplifier... not sure if this makes sense! I think the seller should...