Why not just end the debate,
and use a software tone generator, say like ►►Test Tone Generator Software for Windows / Function and White Pink Noise Generator
and generate tones of the exact frequency you desire, or a series so you can find the threshold of interest.
Or, in case your computer hardware is the limiting factor, get a real hardware tone generator, for some real "old school" analog sine waves. You must know some one with access to physics / electronic test gear?
Failing that, do you have a Theremin handy?