From the overworld if you go into a nether portal and tab out, when the nether loads and sounds that play will be infinitely looped over.
MC-39148
Infinite Sound Loop in Portals
Resolved
Invalid
0
Is this still a concern in the current Minecraft version 1.7.4 / Launcher version 1.3.8 or later? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.