Just depends on the dialect and what era you are talking about. Its a Norse word, which has 2 pronunciations. Yahl-lar-horn: Old West Nordic Gee-yacht-lar-horn: Scandinavian; Iclandic,, which is a direct descendant of the Old West Nordic language. The reason many will say gee-yacht-lar-horn is because that language/dialect is the current, modern way of speech for the area. The guest on Planet Destiny pronounces that way since that's how he has since the beginning. The true pronunciation comes from the words creation from old Nordic times and from the basis of their Mythology, which has it pronounced yahl-lar-horn, which translates into "Yelling Horn" or "Resounding Horn" and is Heimdall's horn used to warn others of intruders. Both ways are correct. One is just more "classic" (if you will) as opposed to the other being more "modern". (I call it Haterhorn...)