A device and method for controlling the audio level of a device are provided. The device includes a housing, a roll unit mounted such that it is able to rotate in the housing, a flexible, touch-sensitive display configured to be rolled on the roll unit around a roll axis so that a first, curved portion of the display forms a side screen bent around the roll unit, and a second, planar portion of the display forms a front screen, wherein the area of the front screen changes according to a rotation of the roll unit, and a controller configured to adjust, in response to detecting a predefined multi-touch gesture on the side screen, an audio output volume of the device.