Fix GSX Pro sound not working in MSFS by checking Couatl routing, Windows volume, GSX audio settings, installation files and headset output.
GSX Pro sound usually stops working in Microsoft Flight Simulator because Couatl is muted or routed to the wrong Windows output, a GSX audio option is disabled, or the installation is incomplete. Trigger an audible GSX service, check Couatl separately in Windows Volume mixer, then restart Couatl after correcting the device.
These checks apply to PC installations of Microsoft Flight Simulator 2020 and 2024. GSX Pro depends on the external Couatl process, which cannot run in the Xbox or PlayStation console versions.
Which GSX sound problem do you have?
The symptoms reveal whether the fault is in Windows, GSX settings or the wider GSX installation.
| Symptom | Likely cause | First check |
|---|---|---|
| MSFS has sound, but every GSX service is silent | Couatl is muted or using another output | Windows Volume mixer and per-app routing |
| Vehicles are audible, but voices or boarding sounds are missing | An individual audio option, event or voice selection | GSX settings and the service stage |
| The GSX menu or services also fail | Couatl or the GSX installation is not running correctly | GSX package links, security blocks and Couatl |
| MSFS and GSX are both silent | Simulator-wide or Windows audio fault | Default output, mixer, drivers and MSFS audio sliders |
If aircraft, ATC and interface sounds are also absent, follow our simulator-wide output and mixer checks first. Reinstalling GSX will not fix a silent MSFS audio device.
How do I restore GSX Pro audio?
Restore GSX Pro audio by testing a real sound event and then checking Couatl as a separate Windows application.
- Start an audible service. Request boarding, deboarding or pushback and wait until the operation has actually begun. Opening the GSX menu alone does not prove that an effect or voice should be playing.
- Test outside the cockpit. Move the camera close to the active vehicle or ground crew. Positional audio, distance and a closed cockpit can make a working sound seem absent.
- Open Windows Volume mixer. Keep the GSX event running, then find the entry associated with Couatl or GSX. Unmute it, raise its application volume and remove any per-app assignment to a disconnected monitor, headset or virtual audio device.
- Check GSX audio settings. Inspect the installed build's volume, voice and output-device controls, where present. Restore automatic or default output if GSX points to an old device. Our guide to GSX menus and global settings explains where general GSX options fit into normal operation.
- Restart Couatl. Use its restart or exit command from the Windows notification area when available, or close Microsoft Flight Simulator and confirm Couatl has stopped before relaunching. Connect the intended headset or speakers before starting it again.
A mistake we see constantly is checking only the Microsoft Flight Simulator volume slider. Windows may treat Couatl independently from the simulator executable, so MSFS can play normally while GSX remains muted or routed through HDMI audio.
Why can I hear MSFS but not GSX Pro?
Microsoft Flight Simulator can remain audible because Couatl may retain a different per-application output device.
Temporarily set one headset or speaker output as both the Windows default playback and default communications device. Remove stale application-specific routing, especially after changing USB ports, unplugging a monitor, switching between speakers and a headset, or reconnecting Bluetooth audio.
With Bluetooth equipment, check that Windows is using the normal high-quality playback endpoint rather than a hands-free or telephony endpoint. Virtual mixers, headset control software, spatial audio and audio enhancements can also redirect external applications; disable those layers briefly to establish a clean test.
Why are only GSX voices or boarding sounds missing?
Partial GSX sound usually means the selected event has not started, one audio category is disabled, or that sound is being attenuated by position.
- Boarding ambience should be tested only after boarding and passenger flow have begun, not while GSX is waiting for doors, stairs or another prerequisite.
- Pushback dialogue occurs at particular stages of the operation, so a silent pause is not automatically a fault.
- Positional effects may be quiet from the flight deck. Test with an external camera beside the active crew or vehicle.
- Voice or language changes should be returned to their automatic or default selection if the problem began after adjusting them.
If the GSX menu shows that a service is stuck before the expected event, troubleshoot the service rather than its audio. When the toolbar, Couatl or all services are failing in MSFS 2024, use our Couatl and toolbar recovery checks.
Should I reinstall GSX Pro to fix missing sound?
Reinstall only after output routing, mixer levels and GSX audio options have been ruled out.
Close MSFS and Couatl, then use the supported installer to update or repair GSX and verify its packages and Community-folder links. This replaces incomplete audio assets and Couatl components without requiring a Microsoft Flight Simulator reinstall; our GSX installation and update procedure covers the safe sequence.
Check Windows security history if files disappear again after repair. For conflict testing, temporarily remove unrelated audio modifications and other non-essential add-ons while leaving GSX's own linked packages in place. Airport and aircraft profiles are not the first thing to delete when every GSX sound is missing, because global silence normally points to output routing or installation files instead.