Chinese listening experiment:
I have some thoughts on developing listening skills versus reading skills.
Summary: any abilities to extensively read and extensively listen, quickly come back if you do the activity again. The things you can extensively read and extensively listen to and understand, will reliably come back after breaks in study. (at least for me)
I learned reading skills first, basically doing what Heavenly Path's Comprehensive Reading Guide suggests: intensive reading where I'd look up hanzi in Readibu or Pleco, extensive reading every so often too (in order to build up reading stamina and ability to read without being able to look words up), from Graded Readers to Children's stories to Webnovels as I gradually increased the reading level. (I really recommend that guide as I learned to read that way, and many other people who've mentioned learning to read Chinese also utilized some of the suggestions in that guide).
My reading skills in Chinese basically developed just like my reading skills in French did except with less cognates from English to rely on lol.
All reading skills developed similarly to how my reading skills in my native language English developed. When I was little, around 5-7, I had a toy where you put a book made for the toy into it and could 'tap the words' with the toy's pen, and the word would be read aloud to me. Which nowadays, you can do on cell phones with TTS, and I used TTS to listen to French and Chinese pronunciations of new words as I read. But back when I was 5, this toy was how I listened to words I read, if I didn't know their pronunciation, and how I heard them out loud to recognize if I knew them. I also learned words in school, from dictionary definitions, as many children do. With word lists, with textbooks and their word definitions we'd have to study, with reading assignments where the teacher told us to find X words we didn't know and write the definition. That was similar to reading French and Chinese later, and looking up the translation/definitions as I read. I got older around 8-10 and I read any books I could pick up at home, or when we'd go to the library, and I started guessing a lot of unknown words from context instead of bothering to look up the meaning in a dictionary. Catwings, Bunnicula, then HP and books assigned in my classes like Holes. Then random books I'd pick up at my house like Michener novels and other dense books for adults I could barely understand, but I sure was getting the 'gist' of the main idea. By 11 I could read fanfiction, and since it was on the computer, I could switch between guessing some words from context and looking some words up by definition online.
I could read Twilight and understand everything except a few words I know I guessed, and I could read books for adults like Dracula, Prince and the Pauper, HG Wells novels, and definitely understood the main idea and most details - though some of the literary analysis elements like themes and symbols escaped me until age 15-16. So by 9-10 I remember being able to read mostly whatever I wanted for the rough main idea, and depending on what the material was it would be frustrating to read more of (like Michener novels or Shakespeare). By age 11-12 I could read pretty much anything I wanted and at least get the main idea and some details, even if I picked up a college textbook or a dense novel for adults or an old novel. By 16+ I could read anything I wanted for the main idea, most or all details, and literary meanings.
Well reading in French followed a similar pattern, except I stopped working intentionally on reading skills once I reached the 'read whatever I wanted for the rough main idea' point. And just over the years as I kept reading, it got to 'read whatever I wanted for main idea and some details' though I'm not confident I could do a literary analysis of the things I read in French. Reading in Chinese followed a similar pattern, which I am still intentionally working on developing my reading skills more, as I would like to grasp the nuance of themes and symbols and imagery and metaphors in the Chinese novels I read. I read French nonfiction mostly and the depth of analysis I want to do is generally only as deep as "what is this historian's opinion of X event, what are they trying to convince me" or "what is this news article writer's opinion of the event." Which is a level of analysis I can do for French nonfiction, so I can do what I want. In Chinese I read a lot more fiction, and I do already notice things like writing style (to a degree), imagery (to a degree), and themes (to a degree), but things like 'references to other works' I will definitely need to learn a lot more to pick up on.
My point is that learning to read pretty much followed the same pattern in all languages. And like with English, the skill of being able to read never really 'is lost.' I have gone 2 years without reading a French book, then pick up a French book and within a few hours the ability to understand all the words I could understand LAST time I was reading comes back. I have gone 6 months without reading a Chinese book, and as long as I pick up something I've read before, the ability to read the words (remember the words and hanzi and grammar) comes back within a few hours of reading.
*I never have any time periods where I totally avoid French or Chinese text - my Google account is in French so I see a little bit of french text every time I check my email, and I watch a LOT of cdramas so any time I see chinese hard subs I see some chinese text. I'm just saying I can avoid reading long form French or Chinese for months, or reading any significant amount of time per day, and within a few hours of trying to read again the reading level skills I had the last time I'd read a lot come back.
Not every word comes back - if I was in the middle of intensively reading a lot, and had looked up 500 words that week when reading a novel, 500 words I did not know well yet, then when I take a break and come back those 500 words will be unknown again. But my extensive reading ability is solid, and stays the same or improves, and I can rely on it. I can rely on being able to read and understand anything in the future, that I can extensively read now. Extensive Reading skills are solid reading skills that like drawing skills, come back even if you take a break.
Now, listening skills. What I am noticing from doing a lot of comprehensible input listening practice is this: extensive listening skills are the same. Extensive Listening Skills, the ability to understand words when listening, comes back within a few hours even if you take a long break from listening.
The words I look up in listening, those are the words I don't know well yet, and I do forget them if I take a break. But the words I have learned to understand easily when extensively listening, I can be fairly sure I will understand again the next time I extensively listen. Even if I take long breaks from listening.
So based on those things, I'd say Comprehensible Input Lessons 'stick' in your memory and the progress isn't 'lost' if you take breaks because... extensive listening skills aren't lost once they're developed. They can get rusty and require a few hours to practice and re-activate what you knew, but the ability to extensively listen isn't lost. However: if someone is using Comprehensible Input Lessons, each lesson obviously is introducing brand new words with new images/gestures/context, and those brand new words if you take a long break probably will be 'lost' and need to be 'relearned.' Just like if you were intensively reading and looked up brand new words, then took a long break from reading. The brand new words in Comprehensible Input lessons need to be repeated to you long enough for them to be 'well understood' and to become words you can recognize in extensive listening to say a podcast with no visuals, in order to be retained. Which is obvious... of course only words you can recognize with no visual aid (comprehensible input lessons or classroom lessons or a tutor), or no word lookups (if intensively studying), are the words you'll retain in long term extensive reading and listening skills.
You'll still HAVE those 'newly learned' words in your memory, since you were exposed to them at least once. And repeated exposure will continue to teach you those words when you come back to listening and reading. It's just they were the words you knew the least when you took the break, so they'll be the hardest to recall/remember and may need some more exposure before you do remember and understand them.













