I saw a mentally handicapped person with one earbud in his ear, and one earbud in his mouth, and I believe he was enjoying the stimulation of the sound on his tongue. It got me wondering if deaf people could be trained to hear with their tongue.
I also then got to wondering whether it could be a fad. It’s a speaker for your tongue and all the kids get one, and then people write music that tickles your tastebuds.