FWIW:
I have a pair of Sony MDR-V6 Studio Monitor headphones. Mine are at least ten years old, and the product is so good that they still make them (which amazes me). You'll see 'em on TV all the time, being used by radio broadcasters, etc.
However, lately I've favored a particular style of Walkman-type headphones...the ones that hook over your ear and have a forward-facing speaker that rests just inside your ear canal. Sony calls these "clip style" headphones. I've got two pair: Sony MDR-J11G and Sony MDR-J10. I find regular earbuds uncomfortable, but I can wear these things all day long because they don't press on your ear at all, nor do they fit tightly inside the ear canal.
These worked well with my band's in-ear monitor system when we were using it, but I have no idea if they'd work well with the bass trainer, since I don't have one.
They have a couple of advantages. For one thing, the conventional-type MDR-V6s have synthetic leather pads that make noise when they rub against my glasses...not so with the clips. If you move your head quickly, the conventional phones are heavy enough to fall off your head...that can't happen with the clip-style phones, which are so light you don't even notice you're wearing them. Also, they let in just enough ambient sound that you don't get that "isolated from the world" feeling. Fidelity is amazingly good considering how cheap they are (about ten bucks).
Hope this helps.