I downloaded your hearing test but there's this wierd crackling noise! (winxp is the only thing in common on the two systems I tested it on, one was a laptop (IBM thinkpad T20) and a computer (clone, SB Live!))
Oh and if the test is functioning properly I can hear the 17.7k-17.8k sounds (my ears hurt -_-') oh and at 19786 hz the sinewazes look like they are a 3D tube!!! (at the high frequinces you can generate come cool looking images :))
some further testing revealed a possible clue, 70hz works perfectly since the sine wave almost dosn't move at all, but when the sineway starts to go a bit crazy the crackling returns.
Awesoken at
The crackling is most likely caused by GDI calls to SetPixel being too slow. It might work if you reduce the window size. Heartest is one of the few programs of mine which doesn't use DirectDraw code ... maybe you noticed it was only 5.5KB. : )
BarrenSoul at
I have to make the window as small as possible (only enough room for the X button) to get rid of the sound :D