Some bugs to be addressed
I used the free version with circumaural headphones. I believe the concept and the GUI are good for a qualitative assessment of hearing and above all for monitoring hearing over time. Nevertheless, it seems there are some bugs in the algorithm. As an example it happened to me during one test that I could hear the sound, clicked on the button and the sound keept increasing in intensity. For that tone the result showed a hearing impairement while I could hear the tone.