We often wonder how moms are somehow able to tell the difference between a baby’s “I’m hungry” cry and “I have a poopy diaper” cry, but according to scientists at Brown University, subtle variations of a cry, that can be imperceptible to the human ear, can really hold important information about a baby’s health. Neurological or developmental defects can change the way infants control their vocal cords, thus affecting how a cry sounds (Cri du chat is one easily detectable example with symptoms similar to Down syndrome).
To learn more about a baby’s health and look for possible neurological or developmental disorders, the scientists created a computer-based cry analyzer that detects the more subtle acoustical differences in an infant’s cry.
The analyzer works as follows:
The system operates in two phases. During the first phase, the analyzer separates recorded cries into 12.5-millisecond frames. Each frame is analyzed for several parameters, including frequency characteristics, voicing, and acoustic volume. The second phase uses data from the first to give a broader view of the cry and reduces the number of parameters to those that are most useful. The frames are put back together and characterized either as an utterance — a single “wah” — or silence, the pause between utterances. Longer utterances are separated from shorter ones and the time between utterances is recorded. Pitch, including the contour of pitch over time, and other variables can then be averaged across each utterance.
According to Brown scientists, the 80 parameters that are measured can each tell something about a baby’s health and could be useful in diagnosing medical problems stemming from malnutrition, prenatal drug exposure, and other risks. Here’s a glimpse at the cry analyzer:
It certainly gives new meaning to the phrase “out of the mouths of babes”!
Journal abstract from the Journal of Speech, Language, and Hearing Research: A Flexible Analysis Tool for the Quantitative Acoustic Assessment of Infant Cry
Article from Brown University: Cry analyzer seeks clues to babies’ health