drill instructor to observe inherent recruit responses to stress, to modify such responses, and to also acclimate the recruit to stressful situations they will experience in combat. Encouraging screaming by recruits also heightens their aggressiveness and trains them to intimidate opponents. Audio level The volume levels of outcries may be very high, and this has become an issue in the sport of tennis, particularly with regards to Maria Sharapova's loud tennis grunts which have been measured as high as 101.2 decibels. The loudest verified scream emitted by a human measured 129 dBA, a record set by teaching assistant Jill Drake in 2000. Unicode See also Battle cry Death growl Howie scream, another often used stock scream Rebel yell Tarzan yell Wilhelm scream, an iconic sound effect used in films dating back to 1951 References External links Oral communication af:Stem#Skree