MASAVE: A mobile test system for audio-visual experiments at home

We present a mobile apparatus for audio-visual experiments (MASAVE) that is easy to build with a low budget and which can run listening tests, pupillometry, and eye-tracking, e.g., for measuring listening effort and fatigue. The design goal was to keep the MASAVE at affordable costs and to enable shipping the preassembled system to the subjects for self-setup in home environments. Two experiments were conducted to validate the proposed system. In the first experiment we tested the reliability of speech perception data gathered using the MASAVE in a less controlled, rather noisy environment. Speech recognition thresholds (SRTs) were measured in a lobby versus a sound-attenuated boot. Results show that the data from both sites did not differ significantly and SRT measurements were possible even for speech levels as low as 40–45 dB SPL. The second experiment validated the usability of the preassembled system and the use of pupillometry measurements under conditions of darkness, which can be achieved by applying a textile cover over the MASAVE and the subject to block out light. The results suggest that the tested participants had no usability issues with setting up the system, that the temperature under the cover increased by several degrees only when the measurement duration was rather long, and that pupillometry measurements can be made with the proposed setup. Overall, the validations indicate that the MASAVE can serve as an alternative when lab testing is not possible, and to gather more data or to reach subject groups that are otherwise difficult to reach.