Hello to you too. On android as elsewhere, it is normal that there is no sound.
This is not a bug. There is no sound yet. I don't know if this is planned.
Personally I add soft music by myself to fully enjoy the "depth" of each moment. Yeah, that sounds weird now that I'm writing it. What would you listen to if you are with a naked girl or a mean boy "hmmm" in your room ?
Hyao nedd perhaps your advice about it :)
It can be more complicated to listen an ambient music with a phone anywhere outside, but listen to the soundtrack of "endless bounty" on steam ... The piano version of the titlescreen music is very cool ;-)