I read rather quickly and I retain while reading the book but it definitely fades over time and when I move on to a new book. I recently started a book of books from another post on here recently. That way I can have my impressions or anything significant to prompt me if I want.

I'm very much a movie goer when I read. The characters all have different voices and I'm completely absorbed when it happens. My kids learned to touch my hand if they wanted to ask me something since I'd be absorbed. I couldn't read when they were toddlers for safety reasons!

I will say reading isn't a competition and you should read how you retain and enjoy. If the voice is helpful for you don't worry too much about it.