It’s not only Sia, of course, she’s just one who has it very prominently,
It’s that roughness, that’s squeak, that almost off sound it’s actually quite appealing… If you listen to chandelier she does it a lot in the first line and then at the 30 second mark when she says love.
Yes, exactly, but with her and many other singers it is controlled, very much a part of why they sound interesting, which is why it feels like it ought to have a name…
This sounds like an overemphasized diphthong, which Layne Staley from the band Alice in Chains also made liberal use of (different musical vein, but the same idea). She’s just digging in and making a soft vowel have a blunt edge to it; re-articulating. It’s also brought further to the forefront by the compression and gain staging of her mic on the recording.
Speaking about that song, I hate it when she does that fake Jamaican accent or like with her voice, sort of like Rihanna, though for the latter it is natural. Does she think it is cute? I hate that type of accent, fine if it is natural.
Sia does creaky voice (vocal fry) and breathy voice both quite a bit. “Breathe Me” is a good example of both.
As for this particular vocal technique, it sounds to me like it’s not a simple diphthong. It sounds more like a combination diphthong and breathy voice kinda thing, maybe.
I dunno. I play musical instruments. I don’t do vocals. I never learned any vocal theory.
I googled a bit, and found a book with a chapter on Sia’s vocal style.
The chapter is entitled “Slave to the Supradiegetic Rhythm - A Microanalysis of Creaky Voice in Sia’s ‘Breathe Me’”.
This analysis predates Chandelier, but may be useful nonetheless.
The topic interests me because I know exactly the singing technique you are talking about and I admire how Sia uses it, but I don’t know if there is a name.
I do think part of the sound you are hearing is Autotune, but that’s not to take away from Sia’s talent.
Yeah, I just looked that one up, and that’s what I think of as vocal fry. The opening line: “Help, I have done it again” has serious fry on “I.” But I don’t hear anything like that at 30 seconds into the song mentioned by the OP.