vchimpanzee said:
I'm not watching that much network TV these days, but at the start of some shows--I know ABC Wednesday night sitcoms are doing this--there is this loud noise that I keep thinking is part of the show, or it drowns out what is being said, and at the bottom of the screen is the "4D" and some kind of illustration.
Hi, longtime reader, first time poster. Actually, that logo says "AD" for "audio description", it probably looks like a 4 because its in a variant of the Avant Garde font (that was most notably used in the logo for the '80s series
Moonlighting) that has an italic-like structure for certain letters. Essentially, ABC is now broadcasting its programs with audio descriptions so that blind people can follow the action that's occurring onscreen. PBS and Turner Classic Movies have used this for years on some of their programs; but on July 1, a new FCC law went into effect legally requiring ABC, NBC, CBS and Fox, as well as their O&Os and affiliates in the 25 largest media markets, and the five highest-rated cable channels (Disney Channel, Nickelodeon, TBS, TNT and USA Network) to offer audio descriptions for the sight-impaired. The descriptions are only audible when you go your TV or digital/cable converter box's audio menu and toggle the Secondary Audio Program function.
This TVNewsCheck article explains it further:
http://www.tvnewscheck.com/article/60097/networks-set-to-launch-video-descriptions