Feynman is talking about "harmonics" in that sentence. "Harmonics" is used in the context of periodic signals. Concerning periodic signals, the human ear has a frequency resolution that goes from 20Hz to 20.000Hz.

If you really wanted to disprove what Feynmann is saying, you should consider a periodic pulse signal of frequency that sits comfortably between 20Hz and 20.000Hz and compare it with a periodic white noise. And clearly you want the two signals to have the same volume, so you would have to run the periodic pulse on a device with a large voltage output so that the pulses are as close as possible to ideal ones.

If you did the above experiment and found a clear difference between the two sounds, maybe you would convince me.

Feynman is talking about "harmonics" in that sentence. "Harmonics" is used in the context of periodic signals. Concerning periodic signals, the human ear has a frequency range that goes from 20Hz to 20.000Hz.

If you really wanted to disprove what Feynmann is saying, you should consider a periodic pulse signal of frequency that sits comfortably between 20Hz and 20.000Hz and compare it with a periodic white noise. And clearly you want the two signals to have the same volume, so you would have to run the periodic pulse on a device with a large voltage output so that the pulses are as close as possible to ideal ones.

If you did the above experiment and found a clear difference between the two sounds, maybe you would convince me.