how is the sound of such thing on bone conduction?
Bone conduction has come a long way. Sound quality for calls/podcasts/audio books is comparable to regular in-ear headphones. Music quality is sufficient for everyday listening - it performs well in highs and mids, however, bass is not as strong.
Have you ever tried bone conduction headphones?
disclaimer: I'm co-founder/CEO of Sentien (the maker of the headset in the article)