…the goal of reading instruction becomes very clear. It must aim to lay down an efficient neuronal hierarchy, so that a child can recognize letters and graphemes and easily turn them into speech sounds. All other essential aspects of the literate mind – the mastery of spelling, the richness of vocabulary, the nuances of meaning, and the pleasures of literature – depend on this crucial step. There is no point in describing the delights of reading to children if they are not provided with the means to get there.
Reading in The Brain, Stanislaus Dehaene, 2009. pg 219https://readinginthebrain.pagesperso-orange.fr/figures.htm
What does it mean to sound out words?
In English, we have an alphabet and each letter makes a sound which is called the sound-symbol connection or the alphabetic principle. We can use the sound-symbol connection to teach reading and spelling. Words like cat, meet, sit, and but that can be sounded out are called decodable words. While not every word can be sounded out, there is still benefit to teaching a sounding out approach.
Although being a good reader involves much more than having efficient decoding skills, it is certainly the case that poor decoding will be an obstacle in developing adequate comprehension skills…weaknesses in letter knowledge and phoneme awareness are two causes of difficulties in mastering reading and spelling skills, and these skills will improve to the extent that these two underlying skills (phoneme awareness and letter–sound knowledge) improve following training.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4538787/
Why does it matter if you can sound out words?
How can I tell if sounding out words is an issue?
Learning how to sound words out can be taught explicitly and with a clear sequence. Some students will excel with this approach, while others may struggle. If it is difficult for a person to sound a word out, be sure to check their phonemic awareness and screen for vision related issues.
Poor readers need highly systematic, structured, explicit, and intensive one-to-one or small-group instruction that recognizes their developmental level in phonemic awareness, word recognition, and comprehension processes. Implicit instruction has been found to be counterproductive with children with learning disabilities or children at risk for not learning to read and produces fewer gains in word recognition and decoding skills than does explicit, intensive instruction based on systematic phonics.http://archive.brookespublishing.com/documents/Birsh_4e_excerpt.pdf
How does sounding out impact learning disabilities instruction?
Most students will benefit from explicit instruction, but people with dyslexia may require additional time and support to learn the rules. Visual and/or auditory mnemonics can be very helpful. If you are working with people who have Down Syndrome or Autism, you may want to start with memorizing whole words and work on sounding out words after a sight word vocabulary has been developed.