Yodeling is a form of singing which involves repeated and rapid changes of pitch between the low-pitch chest register and the high-pitch head register or falsetto. The English word yodel is derived from the German word jodeln, meaning "to utter the syllable jo". This vocal technique is used in many cultures worldwide. Recent scientific research concerning yodeling and non-Western cultures suggests that music and speech may have evolved from a common prosodic precursor.