All four cats here can be very chatty at times, and the three younger ones seem to be getting talkier by the day! Nikki, being Siamese, can of course be quite loud when she really needs to emphasize a point, but these days she isn't the most frequent meower -- that title currently goes to Shadow, who seems to have appointed himself spokescat for the household.
Anyway, I have been trying for a while now to get a video (with audio) of Shadow's meowing. He has a very...unique sound. I have never in my life encountered a cat who sounds quite like he does. His meow is sort of this adorably discordant squeak-yell, combined with the occasional "disappointed R2-D2" sound. Of course I take his communications seriously and always try to figure out what he is trying to say, but it is pretty clear that sometimes he just wants acknowledgment. E.g., part of the reason I haven't been able to get a very good recording of his meyowling until now is because he tends to stop talking as soon as he sees me pointing the camera at him!
But I digress. Below is a video that includes some decent samples of Shadow's very interesting meyowl-squeak-nrrrrr sounds. Cora also pipes up a few times with her little "pleeeeeease!" howl -- both kitties were pleading with me to let them out onto the patio.
Also in addition to the meowing, this video includes some really cool instances of Catspeak body language between these two littermates. There's a really neat "hey sis", "hey bro", "what's up?" head-nose-rub thing partway through.
EDIT: The Siamese cat in this video (which I found randomly on Youtube):
...sounds a bit like Shadow. Similar inflection. I've always thought Shadow sounded a little Siamese-ish but I've also met a lot of Siamese cats who have a much deeper voice. Like many things I'm sure it depends on the individual cat, and with feral-born "mutts" like my younger three you never know what interesting genetics might have gotten into the mix!