Thought Listening

I've been intrigued many times by the fact that they seem to know what i'm thinking. BTW, i just said in a fb post, i figured the guy upstairs is the same guy with the rice van, earlier with the purple Dodge. Looking like Brian Asawi, a deceased Japanese opera singer.

Today i've been browsing again through Bansenshukai and i've been intrigued by a device for listening from the next room, or even through two walls. American walls, of course. I bet they could not do this through concrete (However, in Romania we had the pipes from central heating that were going from one apartment to another through holes in the walls).

Then i just searched and found something really interesting. Besides  the specially shaped cylinder, they have this metal plate that resonates on the frequency of one's voice. Ok, but the title of the post is about thinking, not talking.

Here's the deal. When one thinks, he/she modulates his breath or even moves his tongue in his mouth. I noticed, i expire faster or slower depending what i'm thinking at. The air coming out of my mouth of nose makes a sound that changes frequency accordingly to my thoughts. So what if they learnt to master this as well?

I know, today it can be done by more advanced means. But those can be detected electronically as well. But a simple metal leaf? Maybe different from the one in this video that is used for voice.