tl;dr the thesis is that there's evidence that human screams contain acoustic content in a frequency band unique from other human utterances and are processed by special sensory centers of the brain, which is why hearing them feels uniquely dreadful on a subconscious level
bonus: here's another paper on the same topic that I stumbled across while looking for the first one
We tested this hypothesis by stimulating sleeping human participants with low-intensity screams and neutral calls. We found that screams trigger more reliable and better time-locked responses in wakefulness and NREM sleep.
truly nightmarish methodology here, literally
