Possibly they have a directional microphone. This may seem like high-tech, but it's been around forever, predating cellphones. So someone could have bought it from Radio Shack and learned to use it when they were younger. So if you're talking loudly, and they have a microphone, they can pick it up. Any idea of their former career?
I don't buy the CO idea. CO is more likely to cause headaches, nausea, and skin flushing. And everyone in the house would be showing symptoms too.
Possibly they have a directional microphone. This may seem like high-tech, but it's been around forever, predating cellphones. So someone could have bought it from Radio Shack and learned to use it when they were younger. So if you're talking loudly, and they have a microphone, they can pick it up. Any idea of their former career?
I don't buy the CO idea. CO is more likely to cause headaches, nausea, and skin flushing. And everyone in the house would be showing symptoms too.