If you want more control over the volume on a per-app basis, App Volume Control For you. This app allows you to set specific volume levels within each of your android apps. On the first launch, you will need to enable the accessibility service, through which the application will help you.
By default, the app will show you everything installed on your phone, including system apps. You probably won’t need to change them, so to reduce the clutter you can hit the settings button and disable Show system apps, to see only your installed applications.
Select any app to change its volume into five categories: media (app sounds like in-game music), ring (your phone’s ringtone), alarm clock (your phone’s alarm function), notification (other apps send you notifications), as well as systems (telephone noises from pressing the keyboard, etc.).