Infants generally cry with more variable pitch and duration than adults. Longer, harsher, rougher, and louder cries mean they are experiencing pain or mild discomfort. Hence, a baby's cry with universal acoustic properties is innately decoded by caregivers. In a recent Current Biology study, researchers detected that a baby's cry expresses pain that can be recognized through experience.
About the Study
An analysis was conducted to uncover if individuals having prior caregiving experience with babies were able to identify cries expressing pain. Researchers hypothesized that those with prior caregiving experience are familiar with this process and can easily identify pain cries. To test the hypothesis, cries were recorded from babies in two conditions: mild-discomfort cries during bathing and pain cries while they were administered vaccine sequences.
Psychoacoustic experiments were performed with adult participants with varied experience with babies. The participants were categorized as those with:
- No experience
- Moderate non-professional experience (non-parents who did occasional babysitting or looked after siblings)
- Parents with children at least five years of age
- Parents with babies less than two years of age
- Non-parents with immense professional caregiving experience
All the participants underwent a training phase followed by a test phase. The training was provided over two consecutive days for a few hours, where every participant was subjected to eight different discomfort cries — four per day — from the same assigned baby. Prior research has established that adult listeners quickly become acquainted with an assigned baby's cries after hearing a small number of short crying sequences, and can further accurately identify the assigned baby by listening to their cries alone.
After the training, participants were subjected to a test phase where they listened to new cry sequences — two discomfort and two pain cries — from their familiar baby and an unknown baby. Each participant was asked to classify these cries as discomfort or pain.
Interestingly, the ability of participants to correctly identify the cries depended on their prior and current experience with babies. Non-parents without experience were unable to identify the baby's cry, while non-parents with moderate experience were only able to partially distinguish between the cries — recognizing the pain cry of the familiar baby only. Adults with extensive experience with babies (parents or non-parent pediatric care professionals) could identify the crying context of their familiar baby better than the unfamiliar one.
Notably, parents of babies under two years of age could also recognize the crying context of both familiar and unfamiliar babies they had never heard before.
Conclusions
Caregivers and/or parents with prior experience with babies can identify pain conditions through the use of acoustic information. The ability to decode information from a baby's cries — a key communication signal — comes with experience, shaping auditory and cognitive abilities. Everyone close to a baby, such as parents, grandparents, and relatives, who regularly listen to their cries, can decode and interpret them efficiently.
