So in my story, the "antagonists", I guess you could call them, are 8-9 foot humanoid lizard aliens (yeah fun right?). They are delighted at the sight of the protagonist and make a noise. I'm not an expert in lizards and I was wondering what kinds of sounds lizards make during certain situations. Through a little bit of online digging, I've found out that they trill, squeak, and hiss, but I haven't been able to find any good videos of them making noises. Also, does anyone have any onomatopoeia words for the trill?
I'm not familiar with lizards trilling, so can't really offer onomatopoeia on that. Not that I'm saying it doesn't exist; I only have experience with a certain lizard species. I think hissing is the most common lizard noise, but some of the smaller geckoes and skinks I've dealt with have been squeakers. Some also make more of a clicking noise. And there's always the barking gecko: Are you basing your aliens on any particular sort of lizard (skinks, dragons, monitors, geckoes, iguanas, chameleons, anoles, etc)? That might help in figuring out appropriate noises.
A Chirping perhaps? The reptilian races in my own works do a fair amount of talking (and kicking ass). Though what else would a Militarized group of 7-8 foot badasses from a distant point in the galaxy do? Though they are much closer to dinos, and can growl and roar. But they mostly just talk.
Ah, cool! Thanks for the video! There wasn't really a specific type I was basing them off of, but I heard that geckos are the most vocal so I think that might be better for the situation.
If they're alien, there is no reason that they will sound anything like lizards on Earth, but there would be certain requirements. They'd have to have a large enough vocal range to communicate with each other, civilization can't be built unless the species is social.
One thing you may want to consider with their vocal communication is the sound limitations caused by their physical structure. I remember reading an article a while back saying that reptilians wouldn't be able to make certain noises based on their lack of defined lips and based on their tongue movements (for example, the letters b, m, p, v, and w would be hard to pronounce), meaning that certain sounds would be preferred over others. Depending on the extent to which they are based on lizards, you may also want to consider other forms of communication, such as posture, inflating parts of their body/changing their coloration (such as the beards of bearded dragons), dewlaps/frills etc.
