A captive beluga whale is believed to have made sounds that mimic human speech.
So, marine mammals are smart. Crazy smart. For example, did you know that orcas have developed dialects according to pods, and transient (pod-less) orcas use less complex language to communicate? And there's Old Tom, who was the leader of a pod that worked out a hunting partnership with humans. And dolphins can differentiate between numbers — that's basic maths.
NOC was a beluga whale living at the National Marine Mammal Foundation in San Diego, California. He had been with the foundation for seven years when researchers started to think that they were hearing voices.
One diver, surfacing from NOC's tank, asked "Who told me to get out?" after hearing what he thought was a voice repeating the word "out" under the water — which led to the discovery that the human-sounding vocalisations were coming from NOC himself. The sounds were in a much lower range than what is usually used by whales, which led scientists Sam Ridgway, Donald Carder, Michelle Jeffries and Mark Todd (PDF) to believe that NOC was mimicking the sounds he heard humans make — and to wonder how he was producing those sounds.
It turned out that NOC was increasing air pressure in his nasal tract, making small adjustments in his phonic lips (vibrating membranes within the nasal cavity) and over-inflating the vestibular sacs at the top of the cavity.
Interestingly, NOC only produced the sounds for about four years from 1984, stopping when he reached sexual maturity.
NOC passed away in 2007, but you can hear his vocalisations in the recording below. It sounds like he's singing some sort of adorable fanfare before babbling randomly. Is that really how we sound?