The sound is great as for me in both directions. Background noise are well controlled (as much as on my iPhone 5S I think).
If you are not accustomed to this kind of device, you'll know that you'll very quickly. It allows for more intimate conversations with the phone (no need to yell to be overheard), but mainly frees the hands, which is very handy indeed essential in many cases (car, work, hobby , children, VIDEO GAMES and so on ...)
Very good buy.