When an Ender Dragon Head is hit by a Shulker's projectile, the Iron Golem 'hurt' sound plays.

Recreate:
Creative mode- Use shulker spawn egg.
Place dragon head very near the shulker- see attached screenshot.
Stand on the other side of the dragon head so it is between you and the shulker.
Do /gamemode survival.
The shulker fires its projectile and hits the dragon head. Iron golem sound plays.