Hirono’s got a two-fer going on. Not only is she despicable, her voice is cringe-worthy.
She has a real harsh pronunciation of her “S” words or “sibilant” sounds. Obozo had the same trait whistling like a groundhog. He was merely annoying to listen to whereas Hirono actually hurt my ears.
(Think of the Gopher character in Winnie-the-Pooh voiced by Howard Morris.)
Zero's whistled S is probably something he learned speaking Indonesian - I've heard it with native I. speakers.
I didn't notice Hirono's S, but it could be cultural too. If her family isn't long removed from Japan, I would expect an S sound made with the tongue a little looser on the upper palate than an English S.