Human-level Vocalization through insect-like methods. Possible or absurd?

Question

I'm making a species of sapient human sized creatures that look and act like insects in many ways (except the majority of their entrails, because scaling up arthropods is probably even harder to achieve than making a functional dragon, but that isn't really the point here). However, while I've given them certain traits that would normally be present in vertebrates but not in arthropods, I don't want to give them vocal cords or a syrinx, yet I wished for them to have a complex sound-based system of communication (they need to be able to interact with other, more human-esque species of sapient beings, the majority of which has a biology and language system much like humans and isn't exactly fluent in "pheromone" or "signaling dance", meaning not being able to emulate a more human-like speech would leave my bug species at the literal mercy of competent translators and/or other communication methods that aren't necessarily as widespread or as practical to use).

As for the alternative means of sound production, earth insects have a series of ways of producing sound, from the simpler adaptations to the legs and wings of crickets to specialized organs like the male cicada's clicking tymbal (which was one of the original inspirations for my concept), and so I planned for them to have specialized structures in their bodies dedicated to producing a number of different tones and sounds that could be structured into something extremely similar to human speech, but I'm not sure if such a complicated concept could actually hold water in this case, especially since, unlike cases like Grey parrots, cases of insects whose vocalizations can sound like human speech is not exactly something that has ever happened in nature, as far as I'm aware.

With that said, my question is the following: within the bounds of our natural world, could an insect-like creature develop structures which are capable of satisfyingly imitating the vocal abilities of a human (as seen in animals like parrots and some corvids) via special changes to their exoskeleton or the development of specialized organs which don't rely on the respiratory system (like seen in cicadas) or am I stuck with having to rely on a larynx or syrinx?

This question is more centered around whether it is possible to achieve such a complex process of sound production to begin with rather than the necessary pressures to originate it. The atmosphere and the planet are both earth like, so soundwaves should work almost exactly like what you'd see on earth.

Answer 1

It depends on what you need them to be able to do.

Do they need to be able to produce sounds that are intelligible to someone that knows only English? Well, that might be difficult.

If they just need to be able to produce something that a) can serve as a complex language, and b) that a human could conceivably learn to understand (but not necessarily speak back)... then absolutely!

To start with, we have the cop-out of having them speak in something like Morse Code (or some other drum language), which requires only the ability to make some repetitive noise. Even without conducive anatomy, your insect people might make do with tapping on a rock. And lest you deem this impractical, the record for Morse code comprehension is apparently 140 words/minute, which is competitive with more "normal" human speech.

But that's boring. If we give them the ability to modulate pitch, that's sufficient for them to speak a whistling language (may change the way you think about birdsong!). Again, humans can and do "speak" such languages.

If you combine the two, you can imagine something approaching a Khoisan language, which again falls squarely into the realm of human potential (at least as far as being able to understand, if not speak, the language, though here one might imagine).

If you're dealing with a first-contact situation, these languages are likely to sound very bizarre, but probably not so much that humans won't figure out fairly quickly that they are a language. Learning that language, on the other hand, may be quite the challenge. They're also going to be very "exotic", but that can be a great plus; embrace it!

The critical aspect is going to be giving your insect-people a frequency range that is compatible with human hearing, but this shouldn't be a serious issue.

Answer 2

Amazingly, it is possible.

But you need really smart bugs.

Background: a long time ago in a galaxy far away, the only sound a PC could produce was a buzz, i.e. a square-wave that could only be controlled relative to its frequency. Imagine having a long leg with spiny bristles and sawing it against a chitinous carapace - you can control the leg speed, but nothing else. Fast movement, high pitch. Slow movement, low pitch.

Then someone discovered a way of getting more complex sounds out of a very simple sound mechanism. After a while, human voices - well, very distorted human voices - were being generated by a two-level square-wave generator. There was a utility (SPEECH) by an Andy McGuire that was able to produce acceptable phonemic speech synthesis on a 4.77 MHz 8088.

In principle, nothing prevents your bugs from doing exactly the same.

Answer 3

Frame Challenge

Your stated objective is for them to be able to communicate readily with other sophonts. So, you have a species that has the mental capacity for intelligent conversation but lacks the physical ability to form speech.

I wonder if any humans have been in this situation.

Your desire for them to be able to "naturally" speak something that resembles European human speech suggests they are capable of understanding the language, which means they need no assistance to listen to someone else speaking. This means our translation process only needs to be one-way, and that they are able to verify the accuracy of any translation.

All a translation device needs, then, is a mechanism for efficient input. Even today, we're nearly at the point of being able to manage real-time translation between spoken languages, so imagining this in a future with multi-species sophonts interacting (which I assume implies interstellar travel) is hardly a stretch. This is especially true if your insect-people have a special language used to "speak" to a translating device that is easier for software to parse accurately. Or if they just use some less ambiguous means of input, like typing. (Keep in mind that "but it's hard to learn!" arguments don't really make sense; they have to learn to speak this language somehow, anyway.)

Yes, they still need a device, but when is an interstellar tourist not going to have access to basic technology? (If you're doing a "shipwrecked" story, there's going to be incentive for the rest of your cast to learn the insect-person language.) They don't need to rely on another sophont, and they can monitor the accuracy of translation themselves. Besides, a malfunctioning translator is a ready-made hook for adding drama to a story.

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I read a story once — don't recall the author or title, but almost certain it was published by Baen, probably in one of the free stories collections — about a species that communicated by spitting out colored balls. The translators "learn" from, or were adjusted to, their user. One of the characters' translators breaks and he has to use someone else's, which renders everything in an overly belligerent tone. (Disclaimer: I may have some of these details wrong...)