Learn how to say Yoo-hoo correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word yoo-hoo:
a call used to attract attention to one’s arrival or presence:
Yoo-hoo!—Is anyone there?
say ‘yoo-hoo’ to attract attention:
Roz comes in, waving and yoo-hooing
natural exclamation: first recorded in English in the 1920s