[1] : The Collaborative International Dictionary of English v.0.48

yodel \yo"del\, yodle \yo"dle\, v. t.  i. imp.  p. p.
   yodeled, yodled; p. pr.  vb. n. yodeling, yodling.
   g. jodeln.
   to sing in a manner common among the swiss and tyrolese
   mountaineers, by suddenly changing from the head voice, or
   falsetto, to the chest voice, and the contrary; to warble.
   1913 webster yodel
see also:
yodeled yodled yodeling yodling 

[2] : WordNet (r) 2.0

yodeling
     n : singing by changing back and forth between the chest voice
         and a falsetto

Yodeling >> Y Words
Yodeling, definition of term: Yodeling
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