acous·tic also US acous·ti·cal 
/əˈku:stɪk/ /əˈku:stɪkəl/ adjective
/əˈku:stɪk/ /əˈku:stɪkəl/ adjective 1 : of or relating to sound or to the sense of hearing
▪ the acoustic properties/characteristics of a room ▪ acoustic vibrations 2 a of a musical instrument : not having its sound changed by electrical devices
▪ an acoustic guitar ▪ acoustic instruments
b : made with or using acoustic instruments
▪ She loves listening to acoustic folk music. ▪ an acoustic performance of a rock-and-roll song ▪ acoustic musicians
▪ the acoustic properties/characteristics of a room ▪ acoustic vibrations
▪ an acoustic guitar ▪ acoustic instruments
b : made with or using acoustic instruments
▪ She loves listening to acoustic folk music. ▪ an acoustic performance of a rock-and-roll song ▪ acoustic musicians
— acous·ti·cal·ly /əˈku:stɪkli/ adverb
▪ an acoustically perfect room
/əˈku:stɪkli/ adverb ▪ an acoustically perfect room
