Evaluating the User in a Sound Localisation Task in a Virtual Reality Application

Virtual reality (VR) has proven to be a powerful tool enabling the development of immersive multimedia experiences. Initially focused on entertainment, industry and academia have begun to adapt and develop immersive applications for the healthcare domain, with opportunities in terms of condition assessment, diagnosis and intervention. In the context of immersive applications, audio, and in particular spatial audio, plays an important role on the immersion level. In order to process this information, the auditory cortex uses spatial cues encoded in the sound to provide relevant information about the distance, intensity and direction of the sound source. However, many different types of listening disorders can affect this capability. One condition, central auditory processing disorder (CAPD), significantly affects a user's ability to discriminate between different sound sources. People who suffer with this condition, are incapable of processing sounds properly, which may be stressful and frustrating when doing tasks with complex sounds or in noisy environments. This can have a significant impact on a person's quality of life. In this paper, an immersive VR spatial audio application is presented. It enables us to evaluate the ability of users to specify or localise the source of a sound. An integrated sensing system continuously collects relevant data from the user in order to fully understand how to quantify and evaluate spatial auditory skills from a quality of experience (QoE) perspective. QoE gives insight into a user's state and behaviour. To perform a detailed QoE evaluation of the listening task, implicit and explicit metrics were collected from the user. These included: self-reporting questionnaires, localisation performance, and physiological metrics. Data collected from this QoE evaluation gives an insight into a user's abilities to localise sound sources in VR, and also provides information on behaviour and effort (workload) in performing the task.