How Old Are Your Ears?

The New York Times reported this morning on a new phenomenon in the generation gap. Last year a British company developed a high-pitched sound that could only be heard by young people. It was designed to prevent teenagers hanging around stores and annoying or scaring adult customers away. But now that same concept has turned a high-pitched sound into a ringtone that teens can hear without adults ever being aware that a cellphone has even rung.

Apparently this tone is pitched at 17 kilohertz. According to a graphic with the article, most people aged 18-24 hear a maximum frequency of 16.5 kilohertz, and that number goes down with age. The Times also helpfully links to an mp3 of the ringtone, so you can go listen yourself if you want to. I'm a fair ways beyond the target demographic, and I've got only one functional ear to boot, but I could hear a faint sound when I listened. My brother is ten years younger than me (although still beyond the target demo), and he could hear it as well. We couldn't really compare what we were hearing, so I don't know if he heard a louder sound or not. What can you hear when you play the sound?