Can adults identify pain in babies’ cries?

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 the pain that can be actually 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, i.e., 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 in the case of non-parents who did occasional babysitting or looked after siblings, parents with children who are at least five years of age, parents with babies less than two years of age, and non-parents with immense professional caregiving experience. 

All the participants underwent a training phase followed by a test phase. The training was provided for two consecutive days for a few hours, where every participant was subjected to eight different discomfort cries, four a 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. They can further accurately identify the assigned baby by listening to their cries alone.

After the end of the training, participants were subjected to a test phase where they listened to new cry sequences, i.e., 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, it was observed that the ability of the participants to identify the cries for pain or discomfort correctly 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 able to distinguish between the cries partially, i.e., they could only recognize the pain cry of the familiar baby. Nevertheless, 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 familiar and unfamiliar babies they had never heard before. 

Conclusions

Taken together, 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 the baby’s cries, a communication signal, comes with experience shaping their auditory and cognitive abilities. Everyone close to a baby, such as parents, grandparents, and relatives, who regularly listen to the cries, can decode and interpret them efficiently.