Thank you, I've updated instructions. Click on "Test" to selects new sound and play it. Click buttons for answer, it plays sound if answer is wrong. I use it w

Thank you, I've updated instructions. Click on "Test" to selects new sound and play it. Click buttons for answer, it plays sound if answer is wrong. I use it with eyes closed to concentrate on sound. Guess visual indication would be a good start. I've changed it so it marks wrong button with color until next "Test". The idea is not to guess but to start with one sound, make it familiar, add another, etc.