Thank you for this post! I sometimes need to be reminded as I am not a talker by nature. As Nee1 says the book Meaningful Difference is one of the most cited books. I read many books on child development and kept seeing that book cited so I decided to just go ahead and read it myself. It was very good and I highly recommend both books, The Read Aloud Handbook as well.
For those who are worried about non-stop chatter being too much I do remember that in the Meaningful Differences study they said that each family went up and down in the amount of talk. That is, the "talkers" sometimes talked less. I don't remember the exact number, but something like they said 800 sentences an hour one observation period and only 400 in another. The point was that even on their lowest talking day they still talked more than the non talkers on their highest talking day.
I know that at meal time when I read to my baby I easily surpass the recommended amount and that is 3 or 4 times a day for 30 minutes to an hour each time. You'd be surprised how the words can add up when you are reading and talking freely. Therefore, I do still talk but try not to worry if I am not narrating every second of life at times like when I just woke up and haven't had my coffee or when the baby is clearly enjoying concentrating on whatever fun thing he is doing. The point is not to make yourself or your kids crazy. I say that for myself because I often feel overwhelmed wanting to do the best for my son.
But that being said, there is a mom in one of my son's classes who talks constantly to her daughter. It seems very natural and unforced. Her daughter who is barely 2 talks like she is 4. It is quite amazing and gives me motivation to keep talking!