A simple client-side mod that adds keybindings to manipulate sound volume. By default, the keybinds don't have any key bound, but that can be changed in the Key Binds screen, in the Volume Keybinds category.
For each sound source, 3 keybinds are added: mute, decrease and increase. The percentage that should be decreased / increased can be changed in the volumekeybinds-client.toml client config, the
volume_step option.