In the last decades the pure tone aided thresholds and speech-tests become the benchmark of hearing rehabilitation assessment. The limited capability to differentiate of these methods are known for long time. The idea of using cognitive measurements to assess the efficiency and outcomes of hearing rehabilitation comes from the early 2000s. In the last few years we have known a new trend, hearing instruments have speech processing that not only maximize speech understanding but also they aspire to enhance multiple components of the user’s cognition. For clinical research new method was developed to measure objectively the memory capacity and listening concentration. One of the rather simply approach to measure listening concentration is pupillometry. We present our group’s measurement system and our first experiences.