VOA慢速英语:Screams Have Special Place in Brain

bloodcurdling – adj. causing great horror or fear : this is a very common adjective used to describe screams

nightmare – ­n. a dream that frightens a sleeping person : a very bad dream : a very bad or frightening experience or situation

pitch – ­n. the property of a sound and especially a musical tone that is determined by the frequency of the waves producing it : highness or lowness of sound

vibration – ­n. a continuous slight shaking movement : a series of small, fast movements back and forth or from side to side

frequency – [count] technical the number times that something (such as a sound wave or radio wave) is repeated in a period of time (such as a second)

Hertz – [count] technical a unit used for measuring the frequency of sound waves — abbreviation Hz

evolutionary – adj. of, relating to, or in accordance with a theory of evolution, especially in biology.