This issue clones MC-1867.

The bug

When you are in survival mode, and you take fall damage, the client plays a sound and the server plays another, which creates two fall damage sounds.

By the way, there are two separate fall damage sounds, which is not what I am referring to. One of these is called "Something fell" and one is titled "Something trips". If you fall, like, four or five blocks, the trip sound plays. If you fall, like, 20 blocks, the fall sound plays. However, if you fall at least 3.5 blocks at all, both one of these sounds and the generic damage sound will play.

Steps to reproduce

In survival mode:

1. Turn on subtitles (to easily distinguish simultaneous sounds)
2. Fall >3 blocks

 Observe that there are two distinct subtitles, implying there are two different sounds.

Additional Information

Before 1.4.2 and around 1.5 and 1.6 this was not an issue, but has been reintroduced several times into the game. This implies that this is indeed a bug.

Also, technically, there are 3 sounds, one of which the sound of the block you land on, but that's intentional.