Abstract
Letter identification is an early metric of reading ability that can be reliability tested before a
child can decode words. We test the hypothesis that early speech production will be associated
with children's later letter identification. We examined longitudinal growth in early
speech production in 9 typically developing children across eight occasions, every 3 months
from 9 months to 30 months. At each occasion, participants and their caregivers engaged in
a speech sample in a research lab. This speech sample was transcribed for a variety of
vocalizations, which were then transformed to calculate consonant-vowel ratio. Consonantvowel
ratio is a measure of phonetic complexity in speech production. At the age of 72
months, children's letter knowledge was measured. A multilevel model including fixed quadratic
age change and a random intercept was estimated using letter identification as a predictor
of the growth in early speech production from 9±30 months, measured by the
outcome of consonant-vowel ratio. Results revealed that the relation between early speech
production and letter identification differed over time. For each additional letter that a child
identified, their consonant-vowel ratio at the age of 9 months increased. As such, these
results confirmed our hypothesis: more robust early speech production is associated with
more accurate letter identification.