‘Cry analyser’ may signal future health problems in babies
However, now, a new tool for analysing the sound of a baby’s cry could provide clues to crying patterns that might signal health problems.
The cry analyser, developed by researchers at Brown University in the US, can perceive slight variations in cries that a human ear can’t detect. These variations could be used to identify neurological problems or developmental disorders.
“The cry might tell you something you might not otherwise pick up,” said Barry Lester, part of the team that developed the cry analyser.
For example, the system could identify problems in infants who are premature, growing more slowly than normal, or who have been exposed to drugs, he said.
The cry analyser consists of a standard digital voice recorder for capturing crying sounds, and a computer program that analyses the sounds and extracts a suite of information about their acoustic features. The system breaks down the cries into 10-millisecond blocks, and measures the pitch, or fundamental frequency — the rate at which the vocal cords vibrate. The average fundamental frequency for a typical baby is about 300 to 400 Hertz, said Prof Lester.
Two cries can have the same fundamental frequency but still sound different because of differences in the shape and tension of the vocal tract. The brain modifies vocal tract tension via the cranial nerves. “Since the cry is controlled by cranial nerves, now we have a connection between the cry and the brain,” Prof Lester told LiveScience.
The cry analyser measures subtle properties of the babies’ cries that suggest problems with their brain and nervous system. In addition to frequency, the system can measure other characteristics of a cry, such as loudness, timing, and distortion.
Some babies rarely cry because their nervous systems are not reactive enough, said Prof Lester. Others cry very easily.
“You hardly touch them, and they’re already crying hard,” he said.
During the 1950s and ’60s, researchers in Scandinavia noticed that babies with certain abnormalities produced abnormal cries.
The best example is cri-du-chat syndrome, French for “cry of the cat”, a genetic condition in which infants make high-pitched, cat-like sounds. This gave scientists the idea that a baby’s cry could indicate mental disorders.
Prof Lester shies away from saying the cry analyser can “detect” specific mental problems. “It’s not like a blood test,” he said. Rather, it can pick up on early warning signs that a baby may have problems.
The cry analyser is completed but has not yet been released to the public.
After putting the finishing touches on the system, Prof Lester and his colleagues plan to make it freely available online.
