Fences do not play their block placement sound when placed against any other fence. It will make the sound when placed on any other block, however if it is placed on another fence the sound will not play. It is important to note that the sound will play if you shift place the fence against another fence.

Steps to reproduce:
1. Place a fence (any varient)
2. Place another fence (of any varient) against that fence without sneaking
3. Block placement sound will not play