Hi all,
I am not sure this is the best subforum to ask this question but it is certainly a good one. Even if it's not about grammar, it will probably be interesting for others.
I am almost 40 and I have been exposed to English since I was 10. I got on this forum when I was about 20, and I owe this forum a lot of my skills, even though I still make mistakes. About 10 years ago, some of you will remember that I lived in the US for one year. Before I went there, I was already very fluent. I spoke English daily at work, I had American colleagues, and I used to watch movies in English. I would not understand 100% of the words, but enough to follow the story and enjoy the movie. At the end of my year in the US, I had got used to a variety of accents, and my own accent had improved too. I found out with pleasure that would understand parts of songs that had baffled me for years, and I would understand almost all if not all of the dialogues in movies, at least American ones, I had a little more trouble with British actors.
Then I moved to France, and I remember that up to 5 years ago I still preferred watching movies and TV in English because I understood them much better. Then I met my French girlfriend, and my French improved dramatically

, and I was constantly exposed to French TV

. For practical reasons I was now watching fewer and fewer movies in English. I would still write in English most of the time and I would still speak English at work, but not all the time, and not often with native speakers.
Anyway, on a recent flight to the US I had a chance to watch a few movies and I realized my listening abilities had rusted up a bit. I no longer understand all dialogues like when I had just got back from my year in the US. I still understand most of them, but there are quite a few words I miss, or phrases I do not catch, and a few I misinterpret. I am determined to get back in shape

, not because I need it, but because I like it

, and so I guess I'll get into the habit of watching at least one or two movies or TV series a week in English. And here comes the question.
On Netflix, but also on other platforms, I have the choice of whether to show subtitles. I have always preferred watching movies without subtitles, as a way to challenge myself. Similarly, I tend to avoid checking song lyrics until the song has been around for a while, because I want to understand as much as possible without external help.
But I wonder if this is the most effective strategy to improve. When I lived in the US I did not have subtitles

(not even on TV). But there's a clear difference, I could ask people to repeat if I did not understand, and improvement was super fast (weeks). But with movies, all I can do is go back a scene and put the subtitles on, which takes away a lot of pleasure in watching the movie.
So I wonder what the best strategy is:
- watch without subtitles only
- watch with subtitles only
- watch without subtitles, the watch again with subtitles, and then possibly watch again without them
- watch with subtitles, and then watch again without
I found a study supporting the idea that subtitles lead to faster improvement, but the study is very limited, and the journal is also of dubious quality I guess (
http://thedawnjournal.com/wp-content/uploads/2013/12/4-Dr.-Seyed.pdf). So I thought I would ask you about your experiences. Both as teachers (many of you are) and as learners (even more of you are).
What do you think works best? And do you know of any studies that have looked into this question?
Thanks a lot.
bye
Davide