A method of operating a computer controlled by an operating system that provides an audio subsystem allowing multiple applications executed by the computer to exchange audio signals (Xs, Ys, Zs, Xm, Ym, Zm) with multiple sound interface devices, the method comprising: - receiving a first audio output signal (Wo) from a first application; - providing a first loudspeaker audio signal (Xs) to the audio subsystem in dependence on the first audio output signal (Wo), thereby causing a first sound interface device to emit a first loudspeaker sound signal in dependence on the first loudspeaker audio signal (Xs); - receiving from the audio subsystem a first microphone audio signal (Xm) depending on a first microphone sound signal received by the first sound interface device; - providing a first audio input signal (Wi) to the first application in dependence on the first microphone audio signal (Xm); - providing a second loudspeaker audio signal (Zs) to the audio subsystem in dependence on the first audio output signal (Wo) and the first microphone audio signal (Xm), thereby causing a second sound interface device to emit a second loudspeaker sound signal in dependence on the second loudspeaker audio signal (Zs); characterised in that the method comprises: - for each of the first and the second sound interface device (8i, 8k), determining a device connection state indicating whether or not the respective sound interface device (8i, 8k) is available for exchange of audio signals (Xs, Ys, Zs, Xm, Ym, Zm) through the audio subsystem; - determining a set of available sound interface configurations in dependence on the device connection states; and - providing the first loudspeaker audio signal (Xs), the first audio input signal (Wi) and/or the second loudspeaker audio signal (Zs) in dependence on the set of available sound interface configurations. - receiving a first audio output signal (Wo) from a first application; - providing a first loudspeaker audio signal (Xs) to the audio subsystem in dependence on the first audio output signal (Wo), thereby causing a first sound interface device to emit a first loudspeaker sound signal in dependence on the first loudspeaker audio signal (Xs); - receiving from the audio subsystem a first microphone audio signal (Xm) depending on a first microphone sound signal received by the first sound interface device; - providing a first audio input signal (Wi) to the first application in dependence on the first microphone audio signal (Xm); - providing a second loudspeaker audio signal (Zs) to the audio subsystem in dependence on the first audio output signal (Wo) and the first microphone audio signal (Xm), thereby causing a second sound interface device to emit a second loudspeaker sound signal in dependence on the second loudspeaker audio signal (Zs); characterised in that the method comprises: - for each of the first and the second sound interface device (8i, 8k), determining a device connection state indicating whether or not the respective sound interface device (8i, 8k) is available for exchange of audio signals (Xs, Ys, Zs, Xm, Ym, Zm) through the audio subsystem; - determining a set of available sound interface configurations in dependence on the device connection states; and - providing the first loudspeaker audio signal (Xs), the first audio input signal (Wi) and/or the second loudspeaker audio signal (Zs) in dependence on the set of available sound interface configurations.