Output of audio or visual content via local mobile user devices (4a, 4b. 4c, 4d, 4e, 4f), such as a mobile phone and/or a headset, or via output devices (8a, 8b. 8c, 8d, 8e, 8f 8g, 8h), such as a speaker and/or a display, is controlled by a controller (7). The output devices (Sa, 8b. Sc, 8d, 8e, 8f 8g. 8h) are located at different locations within an environment for accommodating users (3a, 3b, 3c, 3d), such as the interior of a car. The controller (7) determines information on a location within the environment of each of the mobile user devices (4a, 4b, 4c, 4d, 4e, 4f) based on wireless signals received from the user devices (4a, 4b, 4c, 4d, 4e, 4f), such as Bluetooth low energy signals, and controls the output of the content based on this.