When you enter a nether portal and the "downloading terrain" loading screen pops up, the sound "travel.ogg" (.minecraft\resources\sound3\portal\travel.ogg) does not play like it used to in 1.2.5 prior. This occurs because this sound was never played in MP in 1.2.5 prior either, and when MP and SP were merged the sound was removed. The sound was accidentally removed, and should be put back.

What I expected:
When I enter a portal, travel.ogg plays while loading

What Happened:
No sound played when I entered the portal.

To Reproduce:
Turn on your volume. Build a nether portal and enter it. Listen to the silence.