According to Wikipedia, Yodeling is a form of singing that involves singing an extended note which rapidly and repeatedly changes in pitch from the vocal[chest register] (or “chest voice”) to the head register (or “head voice”), making a high-low-high-low sound. This vocal technique is used in many cultures throughout the world.
This technique is also used in pop music and The Cranberries’ song Dreams has a yodeling portion sung by Dolores O’Riordan. Other artists who do this method of singing include Celine Dion, Beyonce Knowles and well-known country singers.
Yahoo! has its own case of yodeling that reflects on the way the brand is marketed. In case you missed that Yahoo! yodel, you can simply go to www.yahoo.com and click on the exclamation mark. You should hear the familiar sound that is also used by Yahoo! on its marketing campaigns.