Help Identify a bird

We have parrots in our neighborhood. They're red-crowned parrots and we're used to seeing them (but we still get excited to see them).

Tonight we heard a different sound than normal. I thought it was either the whistling ducks that are thinking of nesting in our Washingtonia palm skirt and then maybe a grackle. But it just sounded like a parrot, but not our parrots.

We finally spotted the pair of them. They were parrots, but they had a yellow head. Their call was less harsh than the red-crowned parrot and they almost seemed to laugh (I think they were laughing at me thinking they were whistling ducks, but well, I tend to be insecure, so ...). They did appear to be smaller than our red-crowned parrots, but only marginally so. They had the squared off tail we are used to seeing in our parrots (in other words, when they flew off, they had a noticeable "parrot profile").

Honestly, if it wasn't for the yellow head and softer voice, I'd have thought they were our normal parrots.

Anyone know what we saw? Alas, we didn't have a camera to get a pick.