This is a short guide on how to change the AIs hearing distance, this controls how far the AI can hear. Start by going to the BP_MasterAIController then in the components tab select the AIPerception. Then click the Senses Config drop down option then the 1 drop down option then the Sense Drop down option and you should see the options shown below.
Hearing range is the distance the AI can hear in centimeters so 3000 is 30 meters. You can increase or decrease as you need.
AI Spacific Hearing Distances
If you want to have different Hearing Distance settings for a spacific AI character you can right click the BP_MasterAIController in the Content Browser and select Create Child Blueprint Class and name the new blueprint.
Then open that new blueprint and follow the steps in the first section of this guide to change its Hearing Distance settings.
Then open the AI character blueprint that you want to use those Sight Distance settings, so for example the BP_Zombie, in the Class Defaults search for Controller and set the AI Controller Class to the new blueprint you created.
Sight Distances
If you want to know how to change the Sight Distances check out the guide linked below.
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