# FMOD Event callbacks not firing when Bus has 0 volume **URL:** \ **Category:** Unreal Engine\ **Created:** [December 16, 2024, 11:57am UTC](https://qa.fmod.com/t/fmod-event-callbacks-not-firing-when-bus-has-0-volume/22414 "2024-12-16T11:57:09Z")\ **Posts on this page:** 1\ **Showing post:** 13
**Author:** ![Connor\_FMOD](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/connor_fmod/32/3685_2.png) [@Connor\_FMOD](https://qa.fmod.com/u/Connor_FMOD)\ **Post date:** [January 28, 2025, 11:58pm UTC](https://qa.fmod.com/t/fmod-event-callbacks-not-firing-when-bus-has-0-volume/22414/13 "2025-01-28T23:58:05Z")
Thank you for sharing the solution! > [@apfelbaum](#): > > do programmer sounds (not set to async) in an action sheet never stop? All instruments on in an action event are async: [FMOD Studio | Working with Instruments - Synchronous and Asynchronous Instruments](https://fmod.com/docs/2.02/studio/working-with-instruments.html#synchronous-and-asynchronous-instruments:~:text=Only%20instruments%20on%20timeline%20parameter%20sheets%20can%20be%20synchronous.%20Instruments%20on%20other%20parameter%20sheets%20and%20action%20sheets%20are%20always%20asynchronous). Programmer instruments should stop even if they are in action sheets: ![image](https://canada1.discourse-cdn.com/flex036/uploads/fmod/original/2X/c/c4270674400d7e05fadc24c4e1acdb6e83cb5225.png) ![image](https://canada1.discourse-cdn.com/flex036/uploads/fmod/original/2X/a/a87fa1d2cda52f5bfd38f040734bb5c32c9898d4.png) I suggest making sure the programmer sound is set up as the following: [Loop region and programmer sounds - #2 by Connor\_FMOD](https://qa.fmod.com/t/loop-region-and-programmer-sounds/20776/2) Hopefully, it will avoid other unexpected behaviour. Please let me know if there is anything else we can do to assist! --- _[View the full topic](https://qa.fmod.com/t/fmod-event-callbacks-not-firing-when-bus-has-0-volume/22414)._