Oxford University Press conducted a research study which concluded that "parents should continue reading to their children up to the age of nine and beyond to help boost their academic results". It is awesome to hear that our intuitive belief now has a firm basis of scientific research.
It stands to reason, of course: when parents read aloud, they will typically choose books that are above the reading level of the child. This will increase the child's vocabulary and grasp of grammar, and it'll also expand their horizons by introducing them to more complex settings, ideas and issues, particularly if the parents take the time to discuss the book in between the reading sessions.
Although children with an auditory learning style will respond best to this exercise, parents should persevere reading aloud to children who do not have a preference for auditory input, as long as the child's other learning needs (for time of day, room temperature, intake, and so on) have been met.
What are your child's learning needs?