Interesting stuff.
I did this test expecting much worse results as I do have some hearing difficulties in certain situations.
For instance, I have extreme difficulty hearing anyone talking behind me. I also have extreme problems where there is much 'background' noise. If in company at any sort of social event I usually cannot make out a simple conversation over the general 'hubbub' going on around. Obviously these problems are negated by using headphones for the test.
I post the print-out for comparison with anyone else doing this.
I also thought it may be interesting to use this test as a measure of my headphones quality.
I went through each band reducing the levels until each was at the lowest I could discern.
I also attach this print-out.
Also, these tests were carried out using the standard in-built soundcard of the PC. My specialised audio card cannot easily be configured to carry sound from a browser.
James