Subjective equivalent noise resistance of mic preamps?

Resistors produce thermal agitation noise or hiss because of the sun sending thermal energy so that electrons can have random thermal motion ie electrical noise. Johnson's noise or thermal agitation noise.


First the objective method. Possibly first described at the paper Fluctuation Noise in Vaccum Tubes [Pearson]. The pre amplifier input is short circuited. The preamp drives another amplifier which drives a VU meter. Then various resistors are connected at the input until power output measured is doubled. This is the objective equivalent noise input resistance of the preamp.


Weighting filters may be added to mimic our ear brain sensitivity to noise wth respect to frequency.


But why not using our ear and brain itself?


Attention: take all precautions to protect your precious hearing apparatus.


Could a subjective equivalent input noise resistance be found by stating off with a short circuited input, then increasing a variable wire wound input resistor until thermal nose loudness becomes subjectively doubled? (Subjectively doubled is much different from objectively doubled, see Steven's law.


Or increasing an input resistor until a just noticeable difference in thermal noise can be detected?


Reference:


Fluctuation Noise in Vacuum Tubes - G. L. Pearson - Bell Telephone Laboratories - New York - July 6 1934