Hearing check

A teacher I know recently taught me an interesting lesson, as teacher tend to do. One day in her classroom, kids were irritated and occasionally calling out, "Turn it off!" The room was silent with (apparently) studiously studying students, though, so she was puzzled. "Turn what off?" Turns out that a student's cell phone was ringing, but she couldn't hear it. That is how I heard about the mosquito ring tone. A ringtone that (most) adults can't hear at that particular frequency, but kids can. 'Course, I can't actually hear it myself, being as ancient and decrepit as I am at 32 years old. It made me feel better that my 16-year-old niece couldn't hear it, either, though. Check it out here--see if you pass the test!