ai_sound

Entity description

This entity makes abstract sounds or smells that can be sensed by NPCs, but not by the player. This can be used to cause reactions in nearby NPCs.

Contexts

Literal Value	Description
1048576	Sound is from Sniper
2097152	Sound is from Launcher
4194304	Mortar Explosion Here
8388608	Only Combine hear/smell
33554432	Explosion (Usually added to combat sound)
67108864	Exclude Combine (Combine don't hear/smell)

Keyvalues

Name (targetname) <string>[ Edit ]

The name that other entities refer to this entity by, via Inputs/Outputs or other keyvalues (e.g. parentname or target).
Also displayed in Hammer's 2D views and Entity Report.

See also:  Generic Keyvalues, Inputs and Outputs available to all entities

Parentname:

Parent (parentname) <targetname>

Specifies a movement parent. An entity will maintain its initial offset from its parent. An attachment point can be added to the end of the name, separated by a comma.

Volume ([todo internal name (i)]) <integer>

How far away this sound can be heard. This is a radius.

Duration ([todo internal name (i)]) <float>

How long the sound persists each time you insert it.

Sound Type ([todo internal name (i)]) <choices>

The type of sound or smell will determine the reaction of NPCs that sense it. The contexts above can be factored into the number and entered manually.

Literal Value	Description
1	Combat: Will cause most NPCs to become alert
2	World: Will cause most NPCs to become alert
4	Player: Feign player audible
8	Danger: Will cause most NPCs to move away from the position of the sound
16	Bullet Impact
32	Carcass
64	Meat
128	Garbage
256	Thumper: causes antlions to run away briefly
512	Bugbait: get nearby antlions' attention
1024	Physics Danger: Scares off npc_metropolice, npc_combine_s, and npc_antlion
2048	Sniper Danger: Scares npc_snipers into their hole
4096	Move Away: Pushes away npc_metropolice, npc_citizen, npc_combine_s, npc_alyx, and npc_barney, npc_fisherman
8192	Player Vehicle: Makes NPCs hear the player & makes npc_metropolice turn towards the sound (only used by prop_vehicle_airboat
16384	Player Comanion Readiness: Low
32768	Player Comanion Readiness: Medium
65536	Player Comanion Readiness: High

Additional sound context (optional) ([todo internal name (i)]) <choices>

Optional settings specifying such things as who can or cannot hear the sound.

• 1 : Only Combine hear
• 2 : Combine cannot hear

Location Proxy ([todo internal name (i)]) <targetname>

The name of an entity to use as a proxy to determine the location at which to make the sound.

If you specify an entity here, the sound will be made at that entity's location (!player included).

Inputs

Parentname:

SetParent <stringRedirectInput/string>

Move with this entity. See Entity Hierarchy (parenting).

SetParentAttachment <stringRedirectInput/string>

Change this entity to attach to a specific attachment point on its parent. The entity will teleport so that the position of its root bone matches that of the attachment. Entities must be parented before being sent this input.

SetParentAttachmentMaintainOffset <stringRedirectInput/string>

As above, but without teleporting. The entity retains its position relative to the attachment at the time of the input being received.

ClearParent

Removes this entity from the the movement hierarchy, leaving it free to move independently.

InsertSound <integerRedirectInput/integer>

Insert a sound in the AI sound list at a specified volume (1-100) which influences detection radius.

EmitAISound

Make the Sound.