Dial Up Modem Handshake Sound - Spectrogram

However, another major reason is that people have repeatedly gone seeking for language-like or human-language-level behaviors in animals, and repeatedly and consistently failed. It is also worth pointing out that detecting language is a great deal easier than understanding language. Something like [this video] is reasonably recognizable as clearly some sort of language even if we have no (unassisted) human idea what it is saying. We can tell with quite high confidence that most animal sounds are not hiding some deeper layer of information content. Such exceptions as there are, like whalesong, take you back to my first paragraph, though. The idea that language is a uniquely human phenomenon may be "dogma", but it is also fairly well-founded in fact. It should also not be that surprising; had another species developed language first, they'd be the ones looking around at their surroundings being surprised they are the only ones with proper language, because they'd probably be the dominant species on the planet. It isn't a "humanist" bias, in some sense that humans are super special because they're humans, it's a "first species to high language" bias, which happens on this planet to be humans.