I saw tis in cx's blog.. Give it a try! interesting. But i never really tried on others.. Only my sis and her husband.. well. they hear lesser than me..
Find out just how far your ears can hear into the range of ultrasonic ringtones. Pretty much everyone should be able to hear the lowest tone (8kHz). Many people should be able to hear up to around 14.1kHz, from around 17kHz upwards we get into the range that only the under 20's can hear!
You are a dog
Or maybe you are a mosquito, you certainly can't be human.
The highest pitched ultrasonic mosquito ringtone that I can hear is 21.1kHz