I've noticed some sounds playing twice ever since I started playing 1.7.2 but couldn't find the cause(s) for them. After trying to reproduce the bug I found at least one of the causes is opening the inventory screen as soon as a sound starts playing, which causes the exact same sound to replay after exiting the inventory screen.
It only seems to work when you open it right at the beginning of the sounds playback, otherwise it does not duplicate.
There may be other causes for the sound doubling but this is all I've found.