The reference to radio was to try and illustrate the difference between telepathy and a structured language. Telepathy provides no opportunity to use ones imagination. Understanding is complete.
Listening to the radio presents a challenge not experienced before with telepathy. Radio forces one to "imagine" the physical characteristics of the people who are speaking. Radio forces one to "define" the environment from which the speaker exists. There are no clues other than the nuances of the language and the tone utilized by the speaker.It is a rich and wonderful experience.
Telepathy provides no opportunity to use ones imagination. Understanding is complete.
That's what I meant by "unfiltered".
I see what you meant in the radio analogy. That may also apply to reading books with no illustrations, or listening to a science fiction story about a strange imaginary place.