Great idea and pretty decent execution with few minor things. First of all there's not indication with what you can interact. I've spent some time figuring out how to get the keys. Also there's no way of checking of what the goal is. Subtitles would be of much help too: I still don't know what I was suppose to get in the end :) I would've added some feedback when hitting something, like a wall or items, considering that blind person would definitely felt those. May be even remove space button altogether and activate sonar only when you hit something. That would be more accurate to moving around by touch. I understand that in jam conditions there was very little time for that but the outside soundscape could be tweaked a little more to make orientation easier. If you'll continue with the concept further I'd suggest an ability to focus on specific sounds. That said I enjoyed playing your game very much even though I felt that it quite vaguely touched the theme :)