Now, if you want, mobs will be spawned with sounds. You can also customize them.
Add these lines to your config.yml if you don't want to lose current settings from the old version:
Code (Text):
# Play sound, while mobs rise?
play-sound: true
# You can modify spawn sound (Not recommended)
spawn-sound:
name: BLOCK_GRAVEL_HIT
loudness: 0.2
pitch: 0.1
delay-in-ticks: 4