A Probe Study on Vocal Development in Two Infants at Risk for Cerebral Palsy.
Helen L Long, Naomi Eichorn, D Kimbrough Oller
PMID 36335437WHAT IT FOUND
Two infants at risk for cerebral palsy showed delayed and variable canonical babbling compared to ten typically developing peers.
The standard 0.15 threshold for onset was rarely met by either group in home recordings, suggesting current criteria may not apply to all-day sampling.
Key findings
01The two infants at risk for cerebral palsy had canonical babbling ratios that were increasingly lower than those of the typically developing comparison group by 12 months.
02Canonical babbling growth was not monotonic; both at-risk infants and several typically developing infants showed unexpected decreases in their ratios between months.
03Fewer than half of the typically developing infants reached the traditional 0.15 canonical babbling ratio criterion by 9 months in all-day home recordings.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
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What it does not show
The study included only two infants at risk for cerebral palsy, making it impossible to generalize findings to the broader population. All-day home recordings captured periods when infants were sleeping or not engaged, which may have artificially lowered canonical babbling ratios compared to laboratory settings. Follow-up data was incomplete; CP2 could not complete formal speech testing due to severe cognitive and motor impairments. The study relied on a single recording day per month, which may not account for day-to-day variability in infant vocalization.
Declared interests
None declared.
The easy way to misread this
Do not assume that a low canonical babbling ratio in all-day home recordings indicates a speech delay. The study found that even typically developing infants often failed to meet the standard 0.15 threshold in this setting, suggesting the criterion itself may not be valid for home-based sampling.