Among the many seemingly small but very useful changes in Windows Phone 8.1 is a rethinking of the ways in which you can interact with the various sounds that come out of your handset. Now, instead of a global volume control, Windows Phone 8.1 supports separate, custom volume settings for the ringer and notifications and for apps and media.
Out with the old...
To understand what's changed, let's look at Windows Phone 8 first. In that and previous versions of the OS, there is only a single global volume control. You can access this control, in the form of an overlay, by pressing either of the Volume hardware buttons on the handset. (All Windows Phone handsets have Volume Up and Volume Down buttons.)
This overlay notes the global volume level (in this case 5 out of a maximum of 30) and has an interactive button you can use to toggle between ring + vibrate or just vibrate. The volume control itself is not interactive: You can only adjust the volume with the hardware buttons.
Previous Windows Phone versions also support a separate volume control for use in phone calls. This control, curiously, goes from 0 (silent) to a maximum of 10.
In with the new...
In Windows Phone 8.1, everything is a bit different.
First, the global volume overlay has changed. The initial view is simplified, and displays the Ringer + Notifications volume (which goes from 0 to 10) by default. Unless you're in an app, in which case it displays the volume foir Media + Apps.
There is a new control on the right, a carat, which indicates you can tap it to expand the view. When you do, you see the new and separate—and interactive—controls for the ringer and notifications (top) and media and apps (bottom), plus a toggle for vibrate.
The volume control overlay works everywhere in Windows Phone, including from the lock screen, as before. And aside from providing separate volume controls for the different sound types, this overlay is also interactive, so you can control those separate volumes using the provided sliders. If you do continue pressing the hardware Volume buttons, however, they still work too of course: But they only impact the volume of media and apps.
Put another way, to control the volume of the ringer and notification sounds, you need to use the slider control in the volume overlay.
The new volume overlay is also available from the mini playback controls that appear when you press a Volume button while music is playing.
But what about phone call volume?
The phone call volume still goes from 0 to 10, as you might expect, and yes, the default overlay you see if you press a Volume button during call utilizes the new overlay.
If you expand that overlay, what you see now is a single volume slider, just for the phone call volume. So you can use this control or the hardware buttons to control in-call volume now.
And there are two separate volume overlays for headphones (and any other wired speakers) and Bluetooth-connected devices like speakers. These are all separate, so if you like to crank the volume on your speakers but keep your handset speaker relatively quiet, each can have its own setting.
Tip: To instantly silence the ringing when you receive a phone call, just press either of the Volume hardware buttons on your Windows Phone handset.
Tip: Windows Phone 8.1 also provides audio leveling functionality, which can help provide more consistent media playback volume, something that can be especially useful for those who have digital music from different sources. To enable this feature, navigate to Settings, Audio and then the Enhancements page. This interface also lets you enable a "flip to silence" feature, which is another way to quickly silence a ringing phone.