I was curious about my own hearing so I just did a quick search online. I found an interesting site that will enable a person to find there own equal loudness curve (30hz-16k). I had to turn up the volume on my computer to hear the 16khz. I can't hear the 30hz, but It may be the cheap speakers for my computer. I don't have headphones, so tonight I will try when there is less background noise.
http://www.phys.unsw.edu.au/~jw/hearing.html