Running MCPE on an LG Nexus 5X.
Normally, ghasts are audible uniformly regardless of distance from the player, but my Ghasts seem to be following the rules of sound proximity and I cannot hear them unless I'm within melee striking distance.
This is essentially making them into creepers that can blow me up from a distance repeatedly while setting me on fire. Except that creepers at least have the courtesy to HISSSS before they turn me into paste.
Thank you for your report. This issue was, however, submitted earlier as MCPE-16899. Please perform a search next time to make sure your bug hasn't already been reported. The parent issue can easily be found by searching for "mcpe unresolved ghast".