Zombie spawn will play 'ambient' sound at higher pitch than stated in the sounds.json

Verification builds: v1.6.0.0 (980905)

Summary: When you spawn a zombie, it will play the 'ambient' sound upon spawn, however this sound always plays at a higher pitch despite the jsons not reflecting it. All future 'ambient' sounds from that mob will play normally, just not the spawn sound.

Impact: Lost control over the pitch of dialogue lines that are on the zombie 'ambient' sound

Repro Steps: Log into a world in creative mode and spawn a zombie.

Observed Results: The first sound you hear is playing at a higher pitch than the future ambient sounds from the same zombie.

Expected Results: First 'ambient' sound and all future 'ambient' sounds reflect the pitch stated in the json