Surface transducers, like the one used in the video and I suspect in the Oda, are not particularly expensive or unusual. I’ve used them quite a bit in art school, and installation work. I designed a room where I wanted it to appear like voices were talking through it,
On the topic of quality, I believe they are overselling the experience. In my experience surface transducer like this doesn’t reproduce low-end very well. Mids, and highs are ok. I’m sure the choice of material makes a difference. But you could buy a sheet of cherry wood, and some framing nails for a fraction of the price.
Volume is a problem too, if you crank it, wood is not pliable like a speaker cone so it’ll start to buzz and vibrate distorting the sound.
I have some bone induction headphones that work on the same principal. Cool technology, but same problem with the bass response. Mostly good for podcasts.