I will limit myself strictly to concrete, fixed aspects, without the involvement of substances, psychological or psychiatric methods, which would determine a person to "think out loud".The basic idea is as follows: I will approach the technique of reading the inner voice, limiting myself strictly to the radio waves that travel through the human brain and are received by a radio receiver that decodes the altered wave.The subject positions his head between the transmitter and the receiver, the radio waves passing through the brain are perceived by the receiver not exactly in harmonic form, the waves acquiring a slightly altered form. These anomalies are decoded by the receiver software and are transformed into text, and then through a voice-to-speech program into sound. First of all, the subject is recorded while speaking or reading, being scanned by a radio device (transmitter-receiver). Thus each word bears a unique imprint in terms of radio waves passing through the brain, consequently when the person speaks in mind (inner voice dialogues), through software you can compare existing data and the altered radio signal, this making it possible to read thoughts if the spectrum matches or if it is slightly similar to those which where previously recorded while the person was talking or reading. This device is extremely useful for people who have lost the ability to communicate verbally, but at the same time can be used as a form of RADIO-TELEPATHY. Another scenario would be the case of sick people who can "communicate" with the devices around them, just thinking about certain things.
Attached is an image to give you an idea:
The image above can be summarized as follows:
Another way is: placing the transmitter and receiver in a single device, so the receiver being equipped with a filter can decode the reflected waves and can transpose them into text or voice.
Keep in mind that the recorded spectrum is actualy the sound spectrum of the radio signal.