https://www.teachingenglish.org.uk/article/comprehensible-input :
Comprehensible input is language input that can be understood by listeners despite them not understanding all the words and structures in it. It is described as one level above that of the learners if it can only just be understood.
https://www.babylon-software.com/definition/roughly-tuned_input/ :
Roughly tuned input is the input which is more complex than learners' current proficiency and stretches the boundaries of their current knowledge. It focuses on authentic use of language in listening or reading passages.
What is the difference between Comprehensible Input and Roughly tuned Input?
Best Answer
This is from a paper by the linguist Laskewicz. Simply: "roughly tuned" is 'harder' or 'more advanced' than "comprehensible".
Your teacher will expect you to understand exactly what was said if s/he is giving you "comprehensible" input.
On the other hand, if s/he gives you "roughly tuned" input, you may not know exactly what was said, but will be learning new ways of saying things - not just vocabulary, new grammar structures, and the correct "sound" of the language.
What is "comprehensible" and what is "roughly tuned" will change for you over time, as you learn more!