Researchers at the University of St Andrews have taught Janice, Zola, and Gandalf, three squidgy gray seals, to sing Twinkle Twinkle Little Star and the Star Wars theme song – all in the name of science.
The team wanted to see whether the seals could copy melodies and the formants in human speech. “Formants are emphasised frequency bands in our speech sounds,” study author Vincent Janik explained to New Scientist. “They are parts of our speech sounds that we modify to encode information. For example, different vowels only differ in their formants.”
The researchers monitored the three young seals from birth to determine their natural vocal repertoires. They were then trained to copy sequences of the sounds they naturally make, melodies composed of these sounds, and human vowel sounds. Training a seal to copy tunes is quite a lengthy process, but once they got the knack, the three study subjects were pretty good at picking up new sounds.
Zola, a female, was the star singer, managing to copy as many as 10 notes from the childhood classic Twinkle Twinkle Little Star. Meanwhile, Gandalf and Janice managed to copy various combinations of human vowel sounds with accuracy. The findings are published in Current Biology.
“I was amazed how well the seals copied the model sounds we played to them,” lead researcher Dr Amanda Stansbury, who now works at El Paso Zoo in Texas, said in a statement. “Copies were not perfect but given that these are not typical seal sounds it is pretty impressive. Our study really demonstrates how flexible seal vocalisations are. Previous studies just provided anecdotal evidence for this.”
On the whole, mammals aren’t brilliant at copying formants – even the great apes, our closest relatives, struggle – so some scientists argue that advanced learned control over formant production is a feature unique to humans. However, it seems seals are rather talented vocalists, which throws doubt on this assumption and sheds light on the evolution of vocal learning, a key part of language development in humans. What’s more, the seals use the same throat structures as humans to copy sounds.
“Surprisingly, nonhuman primates have very limited abilities in this domain,” Janik explained in a statement. “Finding other mammals that use their vocal tract in the same way as us to modify sounds informs us on how vocal skills are influenced by genetics and learning and can ultimately help to develop new methods to study speech disorders.”
Who knew teaching seals to sing Star Wars could be quite so informative?