A team of researchers have developed a computer-based cry analyzer capable of detecting the nuances in a baby's cry that, while mostly imperceptible to the human ear, hold a wealth of data regarding a baby's health and development.
In doing so, the researchers, which hail from Brown University and Women and Infants Hospital, hope their tool will lead to new ways for researchers and clinicians to use crying to identify children with neurological problems or developmental disorders.
"There are lots of conditions that might manifest in differences in cry acoustics," said Stephen Sheinkopf, assistant professor of psychiatry and human behavior at Brown, who helped develop the device. "For instance, babies with birth trauma or brain injury as a result of complications in pregnancy or birth or babies who are extremely premature can have ongoing medical effects. Cry analysis can be a noninvasive way to get a measurement of these disruptions in the neurobiological and neurobehavioral systems in very young babies."
The system works by operating in two phases. During the first phase, the analyzer separates recorded cries into 12.5-millisecond frames, each of which is analyzed for several parameters, including frequency characteristics, voicing and acoustic volume.
The second phase then uses data from the first to give a broader view of the cry as well as reducing the cry to its most useful parameters. The frames are put back together and characterized either as an utterance - a single "wah" - or silence, with longer utterances being separated from shorter ones and the time between utterances recorded. Pitch, including its contour over time, and other variables can then be averaged across each utterance.
All told, the system evaluates for 80 different parameters, each of which may contain insights into the baby's health.
"It's a comprehensive tool for getting as much important stuff out of a baby cry that we can," said Harvey Silverman, professor of engineering and director of Brown's Laboratory for Engineering Man/Machine Systems.
To understand what important stuff to look for, Silverman and his graduate students Brian Reggiannini and Xiaoxue Li worked closely with Sheinkopf and Barry Lester, director of Brown's Center for the Study of Children at Risk.
Because neurological deficits change the way babies are able to control their vocal chords, those tiny differences might manifest themselves in differences in pitch and other acoustic features.
"The idea is that cry can be a window into the brain," Lester said.
A paper describing the tool was published in the Journal of Speech, Language and Hearing Research.