Скачать или смотреть 1 hour of E1, E0, E-1 and E-2 - ft. Gigachad

No, that is not a downpitched diesel engine.

E1: 41.2 Hz
E0: 20.6 Hz
E-1: 10.3 Hz
E-2: 5.15 Hz

In case you wonder how you are hearing the E-1 and E-2: You are actually hearing the overtones of those notes. The brain sort of fills in the gaps. Similar to how you can hear bass notes even on bad audio devices which are not capable to produce the fundamental. The sound quality suffers, but its audible. With the equalizer i was able to recover the harmonic overtones of the E-2. So what you are hearing is not just a drumming sound or a clicking that is typical for techniques like ingressive phonation or vocal fry, but actually harmonic overtones. So even tho this was not the intention of this video, it does prove that it is technically possible to produce actual notes in the -2nd octave (and possibly even lower) with the voice, if you are willing to put some effort into editing. Whether that makes those notes useful depends on what you are trying to do i guess.