You’ve heard about the new “stealth ring tone” that the kiddies are using on their cell phones to get calls and text messages without their teachers hearing it?
With a modern enough cell phone, the ring tone is so high-pitched that “grown up” ears supposedly can’t hear it. The older our ears get, the more loss of hearing we have in the upper- and lower-most segments of the audible spectrum.
Here’s the tone [20060610_RINGTONE.mp3], can you hear it?