Almost All Sounds, which should be played when your're going into shallow water and out from that water as well, ARE too quiet, comparing to rest all other sounds.
But in the same time, sound of pour water has a nomral gain volume level
Environment
windows 7 32bit all updates, java 7 update 9, realtek hd audio
This ticket has been marked as a duplicate of MC-11817, in favor of the better description/information provided.