Steps to reproduce:

1. Set your synth driver to a Microsoft Speech ApI 5 voice, with audio ducking enabled for sounds/speech.
2. Play a constant sound with constant volume (eg music)
3. Use your computer, note that audio ducking does not occur when speech occurs

Actual behavior:

Audio does not duck on speech

Expected behavior:

Audio ducks on speech

System configuration

NVDA installed/portable/running from source:

NVDA version:

Present in alpha-23874,d8dc04c7, NVDA 2021.2

Windows version:

Windows 11 22000.194

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

Other information about your system:

Other questions

Does the issue still occur after restarting your computer?

yes

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

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?

yes