Resourcepack not playing any Custom sounds

When I try to play a sound with the /playsound command, I hear the normal sound, and not the custom sound.

Steps to Reproduce:
1. Get a resourcepack that works in 1.6
2. Get a commandblock or just type the command, In this summary I'll use the sound "Chicken Hurt", so: /playsound mob.chicken.hurt johano1rct. You won't hear your custom sound, but just a chicken.