Why doesn't my Impulse listener react?

Source channel and listener mask must overlap. Source channel = bit (e.g. 1=0b0001), listener mask filters which bits to accept. AND must be non-zero.

How do I declare custom channels?

Edit Project Settings → Cinemachine → ImpulseChannels asset. Add named channels (Explosions, Footsteps). Both source and listener pick from this list.

Default channel is index 0 (Default). New sources/listeners default to this channel; mask 1 listens. Switch when you need separation.

Fix: Cinemachine Impulse Channel Mask Mismatch

Quick answer: Source channel + listener mask must overlap. Default channel = bit 0; mask 1 listens. Custom channels via ImpulseChannels asset.

Explosion source on channel "Explosions". Camera listener on default mask. AND = 0. No shake.

The Fix

Project Settings → Cinemachine → Impulse Channels:
  + Default
  + Explosions
  + Footsteps

ImpulseSource (explosion prefab):
  Default Channel:  Explosions

CinemachineImpulseListener (vcam extension):
  Channel Mask:     Explosions | Footsteps   // listen to both

Mask is multi-select. Listener can subscribe to several channels; source emits on one. Bitwise AND non-zero = listener wakes.

Verifying

Trigger explosion: vcam shakes. Trigger footstep on disabled channel: silent. Confirms scoping works.

“Channels overlap. Mask listens. Shake fires.”

Related Issues

For Impulse listener, see listener. For Confiner2D, see Confiner2D.

Channels overlap. Listener fires.