Noc was just one year old when he was captured and placed in an open-ocean pen at the US National Marine Mammal Foundation in San Diego, California.
Noc, the white Beluga whale could mimic human voices. Photo Credit: US Navy
After seven years at the foundation Noc began to make unusual sounds spontaneously, a report in the latest issue of the journal Current Biology reported.
Researchers at a San Diego aquarium were baffled by the muffled conversations they kept hearing under and above water. But when a diver thought he was told to get “out” of the water they realized the chatter was coming from Noc.
After that, his speech-like sounds were recorded in air and underwater. Noc started making the sounds in 1984 and continued making them for another four years.
He died five years ago but researchers have just now analyzed Noc’s archived sound recordings.
“We interpreted the whale’s vocalizations as an attempt to mimic humans. The whale vocalizations often sounded as if two people were conversing in the distance just out of range for our understanding,” the authors said.
“These ‘conversations’ were heard several times before the whale was identified as the source.”
It is the first time acoustic recordings showed how such sounds emulated speech and deviated from the usual calls of the species, the researchers said.
They show the speech-like sounds were at fundamental frequencies several octaves lower than normal whale sounds, and much closer to those of the human voice.
Also, whales talk to each other by blowing air through their noses rather than using a larynx, as people do.
“We do not claim that our whale was a good mimic compared to such well-known mimics as parrots or mynah birds,” the researchers said.
“However, the sonic behavior we observed is an example of vocal learning by the white (Beluga) whale. It seems likely that Noc’s close association with humans played a role in how often he employed his human voice, as well as in its quality.”