[grujicd]

Close friend who was on the spot described it as car or plane running towards you, you don't only hear it, you also feel vibrations in the body creating panic and fear.

All demonstrations of LRAD I heard on youtube were with high pitched sound, not a "whoosh" as witnesses experienced last night in Belgrade. Can these devices play any kind of sound?

What is described by victims, and what can be heard on some recordings from last nights, sounds more like Vortex Cannon:

https://www.youtube.com/watch?v=GJpChS-_RJg

[user_7832]

I’m moderately suspicious of the details some people/articles say. Long story short, there’s 1-4khz audio weapons (LRAD), and microwave/heat based ADS. It appears that both of these were used, a Reddit army vet commented about how that’s apparently the “protocol” as the ADS is strong enough to pick off the last stragglers.

I’m ever so slightly suspicious of the “low frequency sound weapon” aspect because that typically takes a lot of energy (I’m speaking from an audio background). However the reports of feeling uneasy do match that of infrasound… yet typically (based on what I’ve read) infrasound doesn’t have an instant reaction but takes some time for people to feel it.

https://en.m.wikipedia.org/wiki/Directed-energy_weapon has a lot more info if anyone is interested.

[grujicd]

Earshot NGO analyzed recorded sounds and found 4 of these videos "consistent with Vortex Ring Gun or Vortex Cannon":

https://x.com/earshot_ngo/status/1901661518153781534

Note that many videos didn't record the sound if the phone was further away from that center line.

This is the recording which perhaps captured sound the best:

https://x.com/stonexman/status/1901034916961309148

[user_7832]

Thank you. Before I saw your reply, I saw this discussion and links on r/acoustics which in retrospect seems to be the best likely answer. It being a cannon (and not a speaker based device) would mean it’s closer to a controlled explosion than a speaker playing (really loud) music.

There’s still the questions of “how is it so small” (apparently) but at least some aspects are answered now.