[Science] Aaaaaargh! The true nature of screaming has finally been revealed – AI


Aaaaargh!Lane Oatey/Getty By Chelsea WhyteWhat’s in a scream? The vocalisations people identify as screams share certain sound qualities – a kind of acoustic DNA that tells a listener’s ear that what they’re hearing a scream, even if it isn’t. “Evolutionarily, screams likely originally functioned to startle attacking predators. Research on screams has the potential to help us understand the evolution of emotional communication,” says Jay Schwartz at Emory University. He and his colleagues asked 181 volunteers to listen to 75 vocal sounds that included laughter, crying, moans, groans, and yells from acted sources – like television or movies – and more natural sources, such as a YouTube of a child opening a present and screaming in delight. Advertisement The listeners indicated whether or not each sound was something they considered a scream. “We did not provide any type of definition for a scream because we were trying to get at what it in people’s minds that distinguishes a scream from other types of vocalisations,” says Schwartz, who presented his work at a meeting of the Acoustical of America on 14 May. Read more: You can tell how tall or strong a person by hearing them roar When they analysed the sound files, they found that the ones categorised as screams had acoustic similarities. People were more likely to consider a sound a scream if it was higher in pitch, and had a varied change in pitch, first moving up and then down at the end. For example, 100 per cent of the participants agreed that this sound was a scream. Sounds that maintained a more steady pitch were less likely to be perceived as a scream. Only 58 per cent of listeners thought this was a scream. Rapid changes in amplitude – perceived as a rough, gravelly quality – also tended to be classified as screams more than vocalisations with a smoother tone. This sound was classified as a scream by 64 per cent of the listeners. But 99 per cent of the listeners found this next sound to be a scream. You can hear the harsh texture created by rapid amplitude modulation. Surprisingly, a recording of a whistle was categorised as a scream by 70 per cent of the participants. “It was because the whistle exhibited a lot of the acoustic qualities that we found to be associated with a scream, including high pitch and roughness,” says Schwartz. More on these topics: psychology