It is effective if you are mentally parting. If you are just listening but not engaged you are passively listening to the sounds and speech. So you are learning in different forms while listening. After 2 years and about 2 hours a day of passive listening with another 2 hours of active learning you should be able to hold a basic conversation on a variety of topics that interest you. You should also be able to read novel at about a 4-6th grade level. Just keep on moving
You are able too decode through just listening from hearing repetition. Not only are you learning but you have also learned that you must communicate in order to get what you want. When you are a child you are navigating the world and learn that words get you what you want.
At around the age of 12-13 you have learned too tune out information and background noise and can make a choice of what you want to learn. Some children start the noise filtering around the age of 7.
As adults we can listen while we drive but we might not be engaged nor or we focused on listening because be are not trying to gain something. If I am listening to a book about a romance I might be more interested because I want to use that information for dating in my TL.