This is the area of reading. The argument over phonics first versus look-say has been raging for years, generating enough heat to threaten global warming. But the evidence is available right now to settle the question. Maybe even save the planet. Here are the facts.
Writing is the transcription of linguistic noises into visible squiggles.
The left hemisphere has the capability, starting from infancy, of sorting out specifically linguistic noises from environmental sounds and eventually duplicating the ones that are in its own language. It can be taught to identify the individual vowel and consonant sounds in a word and put their squiggle-equivalents down in the proper order. The left hemisphere can also be taught to look at a lineup of squiggles, produce the equivalent sounds in the proper order and come up with the word. In short, when a person goes through the auditory component of analysis to read or write a word, he is using his left hemisphere to do it. The right hemisphere, specialized for handling environmental sounds, has no need to transcribe them.