I suspect the hissing isn't hostile, more like the hissing of Manul; seems to be an equivalent to meowing in domestic cats.
(, Wed 13 Apr 2022, 4:28, Reply)
Interestingly, there's still a debate on the capability of big roaring cats with partly ossified hyoid bone like this YouTube specimen to produce true purring
Which reminds me of this Swedish research purring.org
(, Wed 13 Apr 2022, 5:11, Reply)
Many years ago I taught myself to purr for minutes at a time, difficult to get the circular breathing right though. I could get a passable sound both in the throat and upper palate as well as lips/tongue.
It really freaked out some cats.
(, Wed 13 Apr 2022, 22:22, Reply)
They often make a snarling sort of sound when they're happy.
(, Wed 13 Apr 2022, 6:22, Reply)