A scream, shout, yell, shriek, hoot, holler, vociferation, outcry, bellow, or raising one's voice is a loud vocalisation in which air is passed through the vocal folds with greater force than is used in regular or close-distance vocalisation. This can be performed by any creature possessing lungs, including humans. There are slight differences in meaning among them; for example, "scream" and "shriek" generally refer to a higher-pitched, sharp sound, used by some birds and other animals, and a "hoot", such as emitted by an owl, usually does not involve words.
A scream is often an instinctive or reflex action, with a strong emotional aspect, like fear, pain, surprise, joy, anger, etc.
In psychology the scream is an important theme in the theories of Arthur Janov. In his book The Primal Scream, Janov claims that the cure for neurosis is to confront the patient with his suppressed pain resulting from an experienced trauma. This confrontation gives birth to a scream. Janov believes that it is not necessary that it heals the patient from his trauma. The scream is only a form of expression of primal pain, which comes from one’s childhood, and the reliving of this pain and its expression. This finally appears through the scream and can cure the patient from his neurosis.
Janov describes the primal scream as very distinctive and unmistakable. It is a “strangely low, rattling and involuntary sound. […] Some people are moaning, groaning and are coiling themselves up. […] One screams as result of all the other times when it had to stay still, was making fun of, was humiliated or was beaten up”. Janov also says that the primal scream has series of reactions; “the patients that could not even say “piep” at home, suddenly feels powerful. The scream seems to be a liberating experience”. Janov noticed this with all his patients. Women who seem to have baby-voices during the therapy are developing with their primal scream a very low voice.
Gregory Whitehead, founder of the Institute for Screamscape Studies, believes that the voice is used to focus the power: “scream used to be a psychological weapon both for you and against your opponent, it raises confidence to the person using it. Creating power with yell is having to affect someone without touching them”. In this case screaming is a protective weapon, as also often used by animals, who scream as an expression of power or during fights with another animals.