In general buttons are very quiet when they are happy. If he is making noise, he is probably not as happy as he could be. One reason (probably the most likely) could be that he is housed with another male. If you do not know the sexes of your birds,you can post a few good pictures of them and I'll try to help.
Another option could be the enclosure he is in - something about it could be bothering him (size, lack of hiding places, location).
If no answer is found there, you could also try either covering the cage at night so it's completely dark, or placing a night light by the cage so he can see all night. Both options might make the problem worse but could also remove it.
