Have you noticed that people speak differently to babies compared to adults? Caregivers, especially mothers, change their speech when talking to young children. How? Their speech includes higher pitch (音高) and a wider pitch range (范围). They use shorter sentences and repeat words more often. You can think of it as baby talk. Researchers have recently discovered that dolphins also use baby talk with their babies.
The research team recorded sounds of 19 mother dolphins living in the Sarasota Bay area. The sounds of the same female dolphins were compared when they were with and without their babies. Chart 1 shows the sound of a female dolphin without her baby. The researchers found that when dolphins were with their babies, dolphin mothers had a wider range of frequencies (频率) of the sound-the maximum (最高 ) frequencies were higher and the lowest frequencies were lower.
The findings mirror the way that humans change the speech when speaking to babies. Dolphin baby talk may have a similar purpose to human"baby talk" it may help babies learn how to phonate. We humans don't only use baby talk with little babies, but with the children who are still learning to speak. As a result, our children are able to talk. That's exactly what happens to dolphins. The changes in speech don't just happen when dolphin mothers stay with very young babies, but also between mothers and babies that are closer to"toddler (学步的幼儿)" age. Another possible reason for using specific pitch is to catch the children's attention. It's really important for a young dolphin to know"Oh, Mom is talking to me now."
The research about baby talk in dolphins reminds us how important it is in humans. Whenever we speak with a young child, how we say things could be as important as what we say.
