flat volume control

(above) the original XP volume control panel requires users to look at two sliders and two mute check boxes to see why the audio is not playing. (left) In the flat volume control panel all volume information is contained in a one slider per source. Spinning the thumbwheel brings all sliders up or down. Hitting mute brings all sliders to zero and changes mute to restore.

The hardware-inspired volume user interface model that is in use across all of today’s operating systems is the source of several usability issues. One of them is that restoring the volume of a muted application can require an inappropriately long troubleshooting process: in addition to manipulating the application’s volume and mute controls, users may also have to visit the system’s volume control panel to find and adjust additional controls there.

The “flat” volume control model eliminates this and other problems by hiding the hardware-oriented volume model from the user. Using the flat model, users use one slider per application to indicate how loud they want the respective applications to play; the slider then adjusts all hardware volume variables necessary to obtain the requested output. This simplifies controlling the volume of—and unmuting—any application, as there now is a single point of control for each application, rather than an entire hierarchy of such points.

In our studies, participants completed all four volume control and mixing tasks faster and with less error when using the flat model than when using the existing hardware-oriented volume control model. Participants also indicated a subjective preference for the flat model over the existing model..

TECH TRANSFER: Flat volume control has been integrated into the upcoming release of the Microsoft Windows Operating system (code name Longhorn/Vista). Here is a video of lead program manager Steve Ball giving an informal 60sec preview of flat volume control running inside the Sep-1-2005 build of Vista
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