Roosters are louder than hens, yes. Not only are they responsible for those early morning crows announcing sunrise, but they reach much louder volumes. Roosters can reach an ear busting 140+ decibels (source). Which has been described as being similar to standing 15 meters from a jet taking off! While hens cluck up a storm at around 70 decibels. If you want to know how to stop your rooster crowing - check out this post explaining how no-crow collars work.