1. (meta-science) If this result mattered, it would be published in the Journal of the Acoustical Society (JASA), which is where all the good marine mammal acoustics work is published. This appears to be a private journal of a particular russian university, which is less than convincing, and single-author papers are always (fairly or unfairly) subject to higher scrutiny. Other weirdnesses: the paper was submitted on 16 AUG, accepted the same day, and "reviewed" within 5 days. This suggests a certain laxity of rigor.
2. This work was done in a small highly reverberant concrete-walled pool. It would be more convincing in free-field, as much of the analysis here is tightly coupled to notions of coherency, which reverberations blow right (so to speak) out of the water. Why their analysis is done in pascals SPL and not dB re 1uPa SPL (as everyone else does) is confusing.
3. There is little to no quantitative analysis of spectral features in the results or discussion. There are also multiple sentences that involve the phrase "we can assume", which I would argue is certainly not the case.
4. That dolphin clicks are spectrotemporally complex is a boring result. The authors fail to demonstrate, and in fact basically don't even claim, the assertion in the HN title.
I'd love to contribute to this kind of thing, but haven't the foggiest notion of how.
I also have to wonder if there's some deep dread that we're going to learn just what a crime our treatment of quite a few species has been, and continues to be. If we face it, gather evidence to support what is currently only a series of likely hypotheses, we might have to change our behavior or learn ugly truths about ourselves.
If we can gamify protein folding (https://fold.it/portal/) and find scientifically useful answers, why not the same with cetacean languages?
If we could get an open dataset of cetacean sounds along with a tagged assessment of the scenario (i.e. how many were around, were they agitated, etc) then this kind of project could be very interesting.
However as far as I know there isn't that much data available for dolphins (and especially not labelled data, though the unlabelled data may be useful as well.)
> As this language exhibits all the design features present in the human spoken language, this indicates a high level of intelligence and consciousness in dolphins, and their language can be ostensibly considered a highly developed spoken language, akin to the human language.
And:
> The results obtained in this study suggest the existence of a similar highly developed spoken language in toothed whales (Odontoceti), based on the similarity of their acoustic signals and morphology.
Maybe even both. What a wonderful day when we crack the code.