Spectrotemporal Modulation Discrimination in Infants With Normal Hearing.
Anisha R Noble, Jesse Resnick, Mariette Broncheau and 4 others
PMID 36218270WHAT IT FOUND
Infants aged 6 to 7 months discriminate sound patterns significantly worse than adults.
The difference is not due to poor frequency resolution, which is adult-like, but to immature sensitivity to changes in sound intensity. This limits the use of current spectral tests for assessing hearing aid or implant efficacy in very young children.
Key findings
01Infants had significantly poorer spectral-ripple discrimination thresholds than adults across all conditions.
02Both infants and adults improved their discrimination thresholds when the modulation depth increased, and the degree of improvement was not significantly different between the age groups.
03The results support the hypothesis that infant frequency resolution is mature, while their spectral modulation sensitivity remains immature.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The study inferred the shape of the spectral modulation transfer function from only two data points (10 dB and 20 dB modulation depths), which requires cautious interpretation. The conclusion that frequency resolution is mature is based on the absence of a significant interaction effect, which could be due to insufficient statistical power to detect a small degree of immaturity. The study does not explain the underlying reasons for the slow maturation of spectral modulation sensitivity. Inattention in infants could potentially confound results, although prior modeling suggests it cannot fully account for age-related differences.
Declared interests
The authors declared no conflicts of interest. The study was supported by the National Institutes of Health.
The easy way to misread this
Do not interpret an infant's poor performance on spectral-ripple discrimination tasks as evidence that they lack the basic frequency resolution needed for speech perception. The study shows that frequency resolution is likely mature in infants, and their poor scores are driven by immature sensitivity to the intensity modulation of the sound patterns themselves.