According to a new study, a human beings scream takes advantage of a sonic property called roughness. This type of sound, in turn, triggers a fear-based neural response. Described as an acoustic niche, neuroscientists Luc Arnal and David Poeppel argue that screams are capable of eliciting responses that other sounds typically cannot. Screams are intensely loud and, quite often, high-pitched.
According to a new study, a human being’s scream takes advantage of a sonic property called “roughness.” This type of sound, in turn, triggers a fear-based neural response. Described as an acoustic niche, neuroscientists Luc Arnal and David Poeppel argue that screams are capable of eliciting responses that other sounds typically cannot.
Screams are intensely loud and, quite often, high-pitched. They have the ability to communicate the whereabouts of individuals who are in great danger or extreme discomfort. However, until now, the scientific basis of these warning sounds remained poorly understood.
Arnal and Poeppel sought to fill in the gaps of our knowledge by investigating the “acoustic signatures” of various screams.
The pair recorded the sound waves of different types of screams, most of which were sourced from popular movies, YouTube clips and volunteers. The team used the recordings to gain insight into the type of neural pathways these screams activated in the human brain.
According to Poeppel, director of the Frankfurt Max-Planck-Institute Department of Neuroscience, the screams “… occupy a reserved chunk of the auditory spectrum.” After comparing screaming noises to other forms of human-borne sounds – from singing to speaking – they confirmed the veracity of this claim. This finding remained consistent, regardless of the language used.
“The only exception and what was peculiar and cool is that alarm signals (car alarms, house alarms, etc.) also activate the range set aside for screams,” explained Poeppel.
The quality of “roughness” extended to the wailing of newborn babies – another cue that is designed to attract our attention.
In psychoacoustics, the roughness of a particular sound refers the rate at which its volume alters. Typical human speech has a loudness in the frequency of four to five hertz, while roughness has much faster changes in loudness (approximately 30 to 150Hz).
Arnal compares the quality of roughness to the strobe lights we see in clubs: “Screams could be considered as strobophones, since they are modulating very fast in an analogous way in the auditory domain.”
The strongest responses were elicited in the fear center of the brain – the amygdala. Intriguingly, non-scream sounds could also be manipulated to trigger these neural pathways, by artificially introducing the quality of roughness.
So, what are the potential applications of this research? According to Poeppel and Arnal, the study findings could pave the way to improving the design of alarm systems. Horror movie producers may even see some benefit.
The study, entitled Human Screams Occupy a Privileged Niche in the Communication Soundscape, was published in a recent issues of the journal Cell.
See full story on viralglobalnews.com
