They are talking, just not very loudly. It depends a bit on the venue, but generally in Germany it's considered polite to keep your voice down in public places

They are talking, just not very loudly. It depends a bit on the venue, but generally in Germany it's considered polite to keep your voice down in public places so as not to disturb the other guests. Plus, many German people like to keep their discussions private (maybe it's a hold-over from the dictatorship).