I already know about SDH since Universal decided to stop using CC on their DVD several years ago.
There are two kind of SDH out there (that I called): CC-style SDH and foreign-style SDH.
“CC-style SDH” means that the text appears at the spot where the actors speak, just like CC on regular DVD – while “foreign-style SDH” and regular subtitles text always stay in middle-bottom of the screen no matter what.
Only difference between SDH foreign-style subtitles and regular subtitles that SDH added noise background, such as knock on the door, phone ringing, etc… that are not shown in regular subtitles.
My biggest gripe on SDH foreign-style subtitles is that it’s real difficult for me to follow whose talking. For an example, 4 people on one screen and one person will say something and you will not know which said that. And if two or more people saying at same time, the text will appears like this:
We have to figure out who said which line. It’s much more pain to watch it.
I have been testing each studio’s Blu-Ray movies since I bought Blu-Ray player. WB, Paramount, Liongate, New Line, Tri Star, and Disney (I’m still working on MGM, 21st Century FOX, and Columbia) does not have CC-style SDH.
And only Universal Studio and Sony Pictures Classics have CC-style SDH.