A death growl (or simply a growl) is a vocal style (an extended vocal technique) usually employed by singers from death metal music genres, but also used in a variety of other heavy metal styles. Death growls are sometimes criticized for their "ugliness." However, the harshness of death growls are in keeping with death metal's abrasive music style and often dark and obscene subject matter. The progressively more forceful enunciation of metal vocals has been noted from heavy metal to thrash metal to death metal.