Nooooo my good dude from the internets !!

It just mean he’s a Cancer Productus

https://en.wikipedia.org/wiki/Cancer_productus?wprov=sfti1

PS: What a fucking weird name to give to an animal. I didn’t know before I checked.

I am not a specialist but it probably depends of the frequency they are working with.

Intuitively I would go for high frequencies, as they carry more energy and are easier to handle in small spaces than low frequencies.

High frequencies mean they can use flat panel "speakers" (totally not speakers but you get the idea). Probably more than a few to create as many chambers as necessary where air can be rapidly compressed to gain heat.

I think you misinterpret the Hi-Fi acoustic part of that company. We’re not talking about music here. Thermo-acoustics is a whole field by it-self. You can’t hack a speaker to make a heat pump.

French startup Equium according to the article.

https://www.equium.fr/