Horror film reactions can range from screams to shrieks to shuddering. A SCREAM is a loud, high-pitched cry usually associated with fear or pain. A SHRIEK is a sharp, shrill cry, often expressing fear or horror. Lastly, shuddering is an involuntary trembling or quivering, usually caused by fear or revulsion. All of these reactions are common responses to horror films and can be seen in audiences around the world.