These companies are most likely lying or exaggerating their capabilities. Since so many people believe in audio eavesdropping anyway, it's in their interest to make the buyers of their software believe they're much more powerful than they really are.
It's the same as how it's good for AI companies to talk about how AIs are just on the verge of ending the world and must be regulated at any cost - more people believing that what they're selling is absurdly powerful is good for sales.