Scientists Have Reported a Breakthrough In Understanding Whale Language – DNyuz

Scientists Have Reported a Breakthrough In Understanding Whale Language

Researchers have identified previously unknown elements of whale vocalizations that may be analogous to human speech, a new study reports.

Sperm whales are giants of the deep, with healthy adults having no known predators. Scientists studying their vocalizations have already picked out key elements of their communication, namely clicks, sequences of which are called codas. Researchers led by Gasper B. Beus of the University of California Berkeley have discovered that these clicks are similar to the human dipthongs and vowels, where one vowel sounds morphs into a different sound, as is the case in the word coin. The researchers also identified two “coda” vowels that were “actively traded” during conversation between whales. They call them the “a” and “i” vowels.

The researchers explain in their paper, published as a preprint online this week, that the first clue that so-called spectral properties could be meaningful for whale speech was provided by AI. The Beus previously developed a deep-learning model that was trained to mimic sperm whale codeas. It also identified acoustic characteristics.

To follow up on the AI’s tip, the researchers analyzed a dataset of 3948 sperm whale codas recorded with hydrophones placed directly on whales between 2014 and 2018. The researchers only looked at one channel of the hydrophones in order to eliminate underwater effects, whale movements and click timing. They also removed the click time from their visualisation to isolate the patterns within the acoustic property itself.

These visualizations vindicated the AI’s prediction: The whales reliably exchanged codas with one or two formants–frequency peaks in the sound wave–below the 10kHz range. These codas were referred to as “vowels” by the researchers. Single-formant codeas are a-vowels, and double-formant codes are i-vowels. The authors explained that this is analogous to the human vowels, which have different formant frequencies. The authors also found “trajectories of frequency” that went up and down in the codas. They compared this to human dipthongs.

Considering that these coda vowel patterns were very distinct and not intermixed, plus the existence of dipthongs, the researchers argue that whales are controlling the frequency of their vocalizations.

“Under our proposed view, whale clicks are equivalent to the pulses of vocal folds in human speech production,” the authors wrote. “In other words, we treat clicks as the source and the sperm whales’ resonant body (the nasal complex, including the spermaceti organ) as the filter that modulates resonant frequencies.”

The analogies to human speech are readily apparent. The authors note, for example, that vocal tone in Mandarin can change the meaning of otherwise identical syllables.

“If we are right, this means the communication between sperm whales can be more complex than thought.

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