The frequency of range, not the loudness is responsible with causing fear every time we hear someone screaming. Human sounds are known to be most relevant and truthful proofs of authenticity, as sounds cannot be controlled by our minds but are rather spontaneous reactions that display our feelings.
A group of postdoctoral students from NY University conducted a study after becoming parents and facing the unpleasant acoustic releases of their infants. Empathy over the suffering has brought them together to question the science behind human screams, which have a very special way of getting our attention and challenging our emotions in ways other noises do not.
Scream science is a completely new area of expertise that offers us precious insights about the inner workings of human beings. David Poeppel, professor of psychology and neural science at NY University embarked on a mission to analyze a wide range of screams from movies, video recordings and other types of media material, in order to observe what triggers us to react this way and how the people around us are affected by our screams.
Media material did not prove enough to unveil the inner workings of human screams, so authors gathered 19 volunteer screamers who got wild in a lab sound booth. Researchers went on with their analysis by measuring the sound properties of screams, versus normal conversation. They measured the scream’s volume and observed how volunteers responded to the sound. Consequently, they analyzed brain images of people listening to screams and were surprised to see that our brains do not process screams the way they usually process normal sounds.
On a regular basis, our brains are used to perceive a sound we hear and deliver it to a particular section dedicated to unlock the meaning of that certain sound. Screams work on different levels, because they have a so called fear-inducing quality to them. Human screams cover a part of the sound landscape that was thought to be insignificant to communication. Common speech patterns have a slight difference in modulation rate while screams can fluctuate wildly and rapidly, being offered “roughness”. Our minds and bodies react to roughness with fear and that is why screams give us cold shivers down our spines.
Screams are sent from our ears to the amygdala, the area of our brains responsible with emotion (fear included). The level of roughness was mapped by the team of researchers to match an exact acoustic description for the way a sound changes in loudness. They observed a huge variation in scream roughness and concluded that this is the landmark of the way our brains process danger sounds. Frequency of range makes screams creepy.
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