I wrote the following post a number of years ago; It has now been approx 4 years since we used Hanen in the Child Development Centre with Badger. While we were there, it's use was limited to be honest, I did use some parts, which I felt were relevant, particularly the sensory preferences. Overall, I would say that it is a good starting point, but would not rely on it completely and independently for reference... there are other things which are as valuable and I still recommend enhancing your own library of visuals and other speech resources as best as you can to develop your child's speech further.
Don't Click to Look Inside! But keep reading to hear more, find the links and see excerpts.
This book is absolutely fantastic, I really cannot recommend it enough. I read, a lot... and as you might be aware, before now, I have not actually posted a recommendation on here, but this is too good not to share, I have been meaning to post for a few weeks now.
Naoki was a young boy when he wrote this using a paper keyboard, he would be/have been considered to be low functioning, in that he was non-verbal to low verbal...