Comparison of a 2D- and 3D-Based Graphical User Interface for Localization Listening Tests

Abstract

Recently, there is a trend in developing new multi-channel formats towards adding additional loudspeakers in elevated positions. While the common 5.1 surround sound system only has loudspeakers in the horizontal plane, more complex systems, such as 10.2 or 22.2, include two or more elevated loudspeakers. When listening to music using a multi-channel playback system, the audio material has often not been produced for the used system, e.g. listening to 10.2 material while using a 5.1 surround system. In such cases, the audio material has to be down- or upmixed. Compared with listening to the original audio material, down- or upmixing affects the listening experience. The localization of sound sources is one attribute that might be affected by down- or upmixing the audio material. In the past, some localization listening tests were conducted by using an user interface depicting a two-dimensional representation of the scene. When it comes to elevated loudspeakers, a third dimension also has to be depicted by the user interface. In this work, an experiment was conducted where participants had to locate sound sources by using two different graphical user interfaces (GUIs). The first GUI consisted of two static images of the scene: a top-view and a front-view. The other GUI had a fully adjustable 3D visualization of the scene. The main purpose of the experiment is to investigate the differences between both GUIs. This includes the time participants spend on each GUI and the difference in the responses. This work is a contribution to the development of new evaluation methods for new and existing multi-channel audio formats and renderers