An Analog Device That Monitors and Removes Profanity From Television Viewing Through Closed Captioning

Alec Watson of Technology Connections examined an old TV Guardian", an analog television device that monitored, removed, and replaced profanity from shows and movies viewed on television.

Are you a prude who can't bear the thought of your children being exposed to naughty language in movies and television, but you just can't bear the thought of missing out on watching stuff as a family? Are you looking for a technological solution to free you from the guilt of exposing your kids to bad words? Is it 1998? Well then have I got the solution for you, the TV Guardian.

Watson explained that this device used close captioning along the length of line 21 in the analog video signal (vertical blanking interval) to spot objectionable words. The device then quickly muted the audio and replaced the offending dialogue with more acceptable verbiage through closed captioning.

Now, when it's turned on and active, it decodes the captioning data from line 21. If it finds a match with one of those objectionable things in its dictionary, the guardian jumps into action and... mutes the audio ...I must admit that this particular form of parental control seems a bit... odd to my ears, but the way it's done is actually pretty clever.

Watson also brings up a salient point about subject matter.

The TV Guardian can't do anything about the content or what's on the screen; it can only ever be a pretty-good but not perfect profanity filter. So I'm somewhat perplexed by the perceived value here. You're still gonna need to screen for whatever you might not want your kids... seeing!