Starting at 8KHz, work your way up until you can't hear the tone: http://www.noiseaddicts.com/2009/03/can-you-hear-this-hearing-test/ I can only hear up to 12KHz so reckon I must have damaged my ears, probably from listening to Discharge.
15 kHz I should be deaf though, spent hours at freeparties with my head in speakers. My eyesight is perfect though
I just tried it on my desktop and I can hear 14 so it helps to have speakers that can play the sound.
http://www.noiseaddicts.com/2008/10/kurt-cobain-ashes-smoked-art-exhibit-natacsha-stellmac/ I wouldnae be smoking nae ****s ashes.