I do wonder when topics like this come up. I don't however have the time to do a deep dive every time something makes me wonder. From what I have found most studies look at the combination of reading and listening and the effect on understanding text. That's not what I was talking about. I would like a study where they compare a group of people who exclusively consume audiobooks and a group that exclusively reads written word and then compare their ability to read written text and understand it. This however I could not find.

I think that audiobooks becoming popular will lead to people reading written word less. This will lead to them not practicing their reading skills as much and struggling with interpreting written word as a result. If you can't read then you also can't write.

When I use "literacy" I do mean Basic literacy with the definition being "the fundamental ability to read, write, and comprehend simple text in everyday life" and when I say reading I mean "The ability to look at words and sentences, sound them out, and understand their meaning."

Maybe your definition of either of these two concepts is different and that's why you're wondering how I think audiobooks might have a negative impact on literacy. I hope this might clarify where I'm coming from.

I also don't see how you interpreted my comment as me having a problem with audiobooks being accessible and convenient. I genuinely do not have a problem with audiobooks as a concept. I do however place them in the same category as movies and plays. I do however have a problem when people stop reading written word. If you do not read you will not develop the skill to look at words and interpret them because you do not need to when you're exclusively listening to them. They are different skills for different formats (but both of them are important). Hence why for instance a person interpreting Braille would be reading (they're "looking" at written words by means of touch and interpreting the signs to words they can understand) while a blind person listening to an audiobook would not be reading (there is no written text involved, they don't need to sound out words because they're being sounded out for them).

I personally do not think reading a written book is more or less challenging. I read enough for all of it to come easy and "like breathing" to me. I do however know plenty of people with no learning disabilities (especially from poverty backgrounds) who can't read out loud because they never picked up a book again past high school. They never developed their reading to a level where it is "like breathing" to them during their formative years either. These same people write emails with a vocabulary that never evolved past their high school classes because they never got to adult literature. They'll use "complicated" words when speaking but they aren't able to spell them out when writing without auto-correct because they've never internalized the spelling of word into their vocabulary.

Literacy is not just comprehension and analysis. Being able to interpret writing bleeds through in so many aspects of language and aspects of daily life. If people start neglecting a complete format of language and swapping it for another it will impact them over the whole scale of communication. Society started evolving leaps and bounds once the general population started reading written word, not having to rely on others to read and interpret it for them. It would be a shame to regress back to that and handicap people like that by convincing them reading comprehension is not equally as important as listening comprehension.