Alpine Call is a term used to describe the traditional vocalizations of mountain dwellers in the Alps. YODEL (5 letters) is a type of singing characterized by rapid changes in pitch, usually between the chest and head voice. ECHO (4 letters) is an acoustic phenomenon in which sound is reflected off a surface, creating a distinct sound. Moe (3 letters) is a type of yodeling that involves a low-pitched, nasal sound. Together, these three terms make up the Alpine Call.