Quality of experience tests of an object-based radio reproduction app on a mobile device

Object-based audio (OBA) provides many enhancements and new features. Yet, many of these require the interaction of the user by choosing and selecting the functionalities in visual representations and graphical user interfaces. Basic investigations on the issue of user experience for OBA within the EU research project OPRHEUS identify the necessary criteria and dimensions. The user experience in object-based media comprises three dimensions: audio, information, and usability experience. During the project a radio app for mobile devices was designed, developed, and tested, which includes many of the end-user features available with OBA. A first Quality of Experience (QoE) test to evaluate the radio app was carried out at JOSEPHS, an open innovation lab located in Nuremberg, Germany. The second QoE test took place at b<>com's user experience lab in Rennes, France. For both investigations, the main objective was to find out how users can access, interact, and appreciate the various new features of OBA. For the first test two typical user and listening scenarios were simulated: mobile listening and at home. As a result, the general acceptance of the new features and functions that come along with OBA is very high. The usability is rated high. Further possibilities for improvements are provided by the test users. The very good perceived sound quality with surround sound over loudspeakers or binaural reproduction over headphones impressed the listeners most, beside all other features. The second test focused mainly on the approach of comparing and evaluating the features from acceptability to acceptance, or from expectations to fulfillment. In the second test, the most appreciated feature was to set fore-to-background balance. This feature was number two in the first test. The importance of speech intelligibility for radio (and TV) is a long known and discussed issue. Now, with OBA and the Next Generation Audio (NGA) codec MPEG-H, solutions are at hand to address it.