Is this allowed ? Using EQ amplifiers like Voicemeter Banana to amplify footstep

What @OldTreeCreeper has linked to only modifies how your headset plays back sounds, and not the actual game's sounds themselves, or its files.

It's similar to how Bloodhound's voice is treated. Say the actor themselves is the game, and the modifiers Respawn use to make her voice sound like Bloodhound's, is the sound software.

After I installed Sonar, it added another sound device for my headset. So now I have the playback device provided by my headset, and one provided by Sonar.