Steps to reproduce:

1. Launch NVDA and an audio stream in the background, e.g. youtube playing music in a browser
2. Press NVDA+alt+delete to mute all apps except NVDA.
   As expected, Youtube is muted.
3. Exit NVDA
4. Start NVDA again
5. Press NVDA+alt+delete
6. Press NVDA+alt+delete

Actual behavior:

2. Youtube stream is muted
3. Youtube stream remains muted
4. Youtube stream remains muted
5. NVDA says "Applications muted" and Youtube stream remains muted
6. NVDA says "Applications unmuted" and Youtube stream is restored (unmuted)

Expected behavior:

At least, at step 5, NVDA should already know that the other apps are muted and it should unmute them.

I really think that NVDA should not store in its config nor manage an additional muted state. For clarity it should be able to mute and unmute directly the sound as configured in Windows Volume mixer. Else people may have muted through the volume mixer and can wonder why they cannot unmute through NVDA. In other words, putting two switches serially leads to a confusing user experience.

I have not tested but we may encounter the same issues with other apps volume management commands.

In #16273, you indicate that you are using the same framework for mute other apps or other apps volume commands than in sound split. IMO muted state and volume of ther apps should not be stored in NVDA's config, nor should they be restored or re-configured at NVDA exit/startup. They should just be a more easy way to control Windows Mixer's parameters. On the other side, Split mode should be set up according to NVDA's config and disabled when NVDA exits since it's a feature that only has sense when NVDA is active; thus it makes sense to manage it internally to NVDA and Windows Volume Mixer should not be touched for Sound Split feature.

NVDA logs, crash dumps and other attachments:

None

System configuration

NVDA installed/portable/running from source:

From source

NVDA version:

Last alpha, commit 3d4a0a8.

Windows version:

Windows 10 22H2 (AMD64) build 19045.4170

Name and version of other software in use when reproducing the issue:

N/A

Other information about your system:

N/A

Other questions

Does the issue still occur after restarting your computer?

Not tested.

Have you tried any other versions of NVDA? If so, please report their behaviors.

No; new feature

If NVDA add-ons are disabled, is your problem still occurring?

Yes

Does the issue still occur after you run the COM Registration Fixing Tool in NVDA's tools menu?

Not tested