Hmm, so 4.5 - 25 Hz are microwaves now? Neat!
I guess on a galactic scale, a 66600 km wavelength is "micro"...
I assume that what was meant there is pulse repetition frequency (PRF). Not to endorse these claims, but they are maybe referring to possible explanations of “Havana syndrome” (q.v.), which is still an open topic.
What was originally meant most likely is sound/vibration, nothing to do with electromagnetic waves. Some idiot grabbed those numbers and applied in a completely irrelevant context.
There are many theories about Havana Syndrome, and pulsed microwave radiation is one serious theory. The jury is still out: https://en.wikipedia.org/wiki/Havana_syndrome .
However that would not explain the sound recorded by someone with a cellphone. Microwaves are not acoustic waves. There are two mechanisms by which a person could theoretically HEAR microwaves themselves (thermal expansion and contraction of bones in the head which then can transfer the mechanical vibrations to the ear drums, or direct electrochemical damage from strong microwave energy to nerve cells in the nerves and brain tissues responsible for processing signals from the ears). However, NONE of this would be able to be recorded by a cellphone's microphone. For one, thermal expansion/contraction noise generated by objects in the same room, would generate sound waves that would be far too weak by the time they traveled through the air to the cellphone's microphone (only a direct mechanical linking such as ear-bones would allow the sound to be detected). Also, direct pickup of the microwave energy by the cellphone's circuits in a way that would be recorded as an audible sound would be very unlikely (internal circuits in a phone are usually shielded by a grounded metal foil layer over the circuits, to make them comply with part 15 FCC regs, so the circuits don't accidentally emit levels of RF that could interfere with other radio reception). Furthermore, I think the person who heard the sound themselves, verified that what they had recorded sounded like what they heard when it was happening. It's unlikely that if there was a microwave generated sound in the person's head, and separately in the phone, that they would sound identical, as the signal conversion mechanism of the oscillations (from electromagnetic to mechanical), would be different between a person hearing it and the phone's microphone "hearing" it.
So this leaves the only viable possibility. That possibility is that a SONIC weapon was in use. Either a sonic weapon with a high, but audible, frequency was being used, or it was using an ultrasonic frequency, that vibrated the surface of some object in such a strong manner that its vibration had a non-linear effect on the material's vibration (like it was driven at 50kHz, but vibrated strongly at 5kHz, due to non-linear mechanical effects in the material).
And yes, that audio recording is real. It isn't just a myth. It actually exists. This is right from the source, linked to from the original AP article.
Here's the article
https://apnews.com/article/health-north-america-ap-top-news-cuba-health-mystery-international-news-88bb914f8b284088bce48e54f6736d84Yet for some reason the news now is pushing the idea that it's microwave, seemingly FORGETTING that they actually have their hands on an actual AUDIO RECORDING from the Havana event. Originally, for a week or two, the news talked about this with the idea it was a sonic weapon, and every time they ran the news story they played this sound recording. Then as soon as the microwave theory was published, they SUDDENLY never again played (or even mentioned) this recording, almost as if they forgot it even existed. My guess, is that the sonic idea was TOO CLOSE to the truth. And the govt was NOT happy that the sonic weapon idea was being discussed by the news, so the govt published a new "study" that suggested microwaves were to blame, and published the study as a press release, to distract the news agencies from the actual sonic weapon being used. And it worked. The news has SUDDENLY forgotten all about the sonic weapon. But why would the govt want to hide the type of weapon? It's not like it's our weapon, as it was in fact being used AGAINST us. But that leads me to think maybe it WAS our weapon, and somehow, Russia or another enemy nation somehow managed to get their hands on it, and the US govt did NOT want it to come out in the news that a technology stolen from us was now being used against us. So the US govt intentionally mislead EVERY NEWS AGENCY, by publishing this fake report, trying to get them to forget the sonic weapon idea.
But trust me. I've NOT forgotten about the possibility of it being a sonic weapon. In fact, that's my BEST GUESS as to the type of weapon it was. It was almost CERTAINLY a sonic weapon.