Unreal Engine 5 Enemy AI #4 – Build a Distraction System with Noise & AI Hearing

Part 4 of the UE5 Enemy AI Series. Learn to build a distraction system with throwable objects, sound cues, and AI hearing perception—all in Blueprints.

Welcome back! In Part 4 of the Unreal Engine 5 Enemy AI Series, we’re stepping into stealth gameplay.
Up until now:

• Part 1 → Enemy Blueprint + AI Sight
• Part 2 → NavMesh + Patrol Paths
• Part 3 → Chasing & Forgetting system

Now, we’ll go further by building a complete distraction system: throwable objects that make noise, proper 3D audio cues, and AI guards that can hear, investigate, and forget if nothing is found.

All of this is done 100% in Blueprints, no C++ needed.

🎯 What You’ll Learn

• Creating a throwable distraction object with UE5 modeling tools
• Setting up 3D sound effects (attenuation & spatialization)
• Adding Blueprint logic to spawn and throw objects
• Configuring AI Perception Hearing
• Making enemies investigate noises then return to patrol
• Organizing project folders for clean workflows
• Debugging & best practices for AI events

📝 Chapters

• 00:00 – Intro & What You’ll Learn
• 00:54 – Creating a Throwable Object
• 02:54 – Setting Up Input Action to Throw
• 04:04 – Adding 3D Sound Effect
• 05:28 – Organizing Blueprints
• 06:12 – Throwable Blueprint Component Setup
• 07:57 – Adding Noise Logic on Impact
• 10:05 – Spawning & Throwing the Object
• 13:00 – Adding AI Hearing Perception
• 14:26 – Wiring AI to React to Noise
• 15:49 – Fixing Forget Logic for Noise
• 16:12 – Refreshing Enemy in Level
• 16:38 – Final Test & Outro

⚙️ Step 1: Create a Throwable Object (Mesh)

1. In Content Drawer, create a new folder → 3DModels.
2. Switch to Modeling Mode (Shift+5).
3. Under Sphere Tool, set:
   • Radius = 10
   • Accept to save mesh directly in 3DModels folder.
4. Rename mesh to MySphere.
5. Double-click to open Static Mesh Editor → Collision → Add Sphere Simplified Collision.

👉 This ensures it interacts with physics & overlaps properly.

⚙️ Step 2: Input Action for Throw

1. In Input/Actions folder → Create Input Action: IA_Throw.
2. Open it → Value Type = Digital Bool.
3. In Input Mapping Context (IMC_Default) → Add Mapping:
   • Action: IA_Throw
   • Key: Q (or any key of choice).

👉 Now the project recognizes a “throw” command.

⚙️ Step 3: 3D Audio Setup

1. Create new folder → Audio.
2. Import sound file (.wav or .ogg, not .mp3).
3. Right-click → Create Cue → BallDrop_Cue.
4. Open cue:
   • Enable Override Attenuation
   • Set Inner Radius + Falloff Distance for realistic fade
   • Adjust Volume if needed

👉 With attenuation on, sound will only be heard near the impact, not globally.

⚙️ Step 4: Create Blueprint – BP_Throwable

1. In Blueprints folder → New Actor Blueprint → name BP_Throwable.
2. Add Components:
   • Static Mesh → assign MySphere
   • Projectile Movement
3. Static Mesh settings:
   • Collision = Block All
   • Simulate Physics = OFF
   • Enable Gravity = ON
4. Projectile Movement:
   • Initial Speed = 1000
   • Max Speed = 10000
   • Should Bounce = ON
   • Disable “Initial Velocity in Local Space”

👉 Ball now behaves like a proper projectile.

⚙️ Step 5: Noise Logic (Impact)

In BP_Throwable Event Graph:

1. Add Event Hit.
2. Exclude player collisions:
   • Get Player Controller → compare with Other Actor → Branch.
3. True branch → Add Do Once (prevents spam from bounces).
4. Add:
   • Play Sound at Location → BallDrop_Cue
   • Report Noise Event:
     • Location = Hit Location
     • Loudness = 1.0
     • Tag = ball
     • Instigator = Player Controller
   • Print String → “We made some noise” (debug).

👉 Each throw now emits sound + noise perception for AI.

⚙️ Step 6: Throwing the Object (Character Blueprint)

In Player Character Blueprint:

1. Add Arrow Component (spawn point). Position:
   • X = 60, Y = 50, Z = 60
2. Event Graph: On IA_Throw Pressed:
   • Spawn Actor from Class → BP_Throwable
   • Transform = Arrow World Transform
   • Collision Handling = Always Spawn (ignore collisions)
3. From return value:
   • Get Projectile Movement → Set Velocity
   • Velocity = Actor Forward Vector × 2000

👉 Ball now spawns & launches in front of player when pressing Q.

⚙️ Step 7: AI Hearing Perception

In BP_EnemyGuard:

1. Select AI Perception Component.
2. Add new Sense Config → AI Hearing Config.
   • Hearing Range = adjust to your map (e.g., 1500–2000).
   • Max Age = 5s (memory span for noise).
   • Detection by Affiliation → Check Detect Neutrals & Friendlies.
3. Optionally → set Dominant Sense = Hearing.

👉 AI now listens for noise events.

⚙️ Step 8: Blueprint – Reacting to Noise

In Event Graph of Enemy:

1. From On Target Perception Updated → break AI Stimulus.
2. Check Tag = ball.
3. If true → Run AI Move To:
   • Pawn = Self
   • Destination = Stimulus Location
4. If false → keep old sight logic (chasing player).

👉 Enemy now investigates noise sources like thrown balls.

⚙️ Step 9: Fix Forget Logic for Noise

• On On Target Perception Forgotten:
  • Remove old Player-only cast.
  • Directly reset speed → Patrol Speed (300).
  • Resume Patrol loop.

👉 Prevents cast failures when AI forgets non-player stimuli.

⚙️ Step 10: Testing & Refresh

1. Delete old enemy actors from level.
2. Drag fresh BP_EnemyGuard into level (ensures no cached logic).
3. Hit Play:
   • Press Q → ball spawns & lands → noise event triggered.
   • Enemy hears → moves to location.
   • If no player seen → forgets after 5s → resumes patrol.

✅ Final Results

You now have:

• Throwable distraction objects 🎱
• Proper 3D sound & AI hearing 👂
• Enemies that investigate noises 🕵️
• Forget system returning them to patrol 🌀

This lays the foundation for stealth mechanics and more dynamic AI behaviors.

🔗 Resources

• 🎵 Ball Drop Sound Effect (Google Drive)
• 📺 Full AI Playlist on YouTube
• 🌐 rambod.net
• 📚 Unreal Engine 5.6 Docs

📺 Watch the full tutorial here:
👉 https://www.youtube.com/watch?v=-3o779k_QMo