I recently had to do an interview in Cantonese with a local radio station. Forty-five minutes! I had never spoken for 45 mintues in Cantonese with anyone, let alone in a radio interview. I had only a few days to prepare, since prior to the interview I was away on holidays. I had also not found anything interesting to listen to in Cantonese.
I probably listened to it for 6 or 7 hours in the few days leading up to the interview. I did better in that interview than I expected, perhaps better than I have ever done in Cantonese.
The power of listening to things THAT INTEREST US is phenomenal.
Of course, if transcripts were availabe, and if I could study these texts at LingQ I would have gained a lot of vocabulary. As it was there were many words that I did not understand. However, in terms, rhythm, timing, comprehension, confidence, I gained a lot, simply by listening. It would not have worked, and did not work, with uninteresting content.