As we age, our hear­ing slowly but surely slips away. Time turns down the deci­bels. But what, ex­actly, does that ag­ing-of-the-ears sound like? What would it sound like to go, in an in­stant, from the hear­ing of a 20-year-old to the hear­ing of a 90-year-old? In the vo­cab­u­lary of fre­quen­cies and deci­bels, what does nor­mal hear­ing loss sound like? After find­ing a set of hear­ing data avail­able on­line,1 we de­cided to de­velop a small web-based sim­u­la­tor to help you ex­pe­ri­ence, in re­al­time, the re­sults of nat­ural hear­ing loss.