Would it be possible to design a device that would filter out television and radio commercials?

It’s been done, it was called TIVO and for a while it was awesome, until they got sued and had to remove the ad filtering.

The technology is already possible in several different ways. But the commercials are a source of revenue stations depend upon, and for companies to think it’s worth paying for commercials, stations need to be able to assure them that viewers are getting something out of the commercials. This is why, for example, (at least so I’ve been told) that DVR fast-forward buttons typically scan through commercials rather than jumping a certain number of second ahead… let alone algorithms that filter commercials out entirely. Or more simply, what AYKM said as I was typing this!

French exchange students stayed with my family for a summer back when I was in high school. I still remember their surprise at how US TV was formatted—where commercials would interrupt the show, and also just how many commercials there were. Back in France, they explained, there would be blocks of commercials between programs, but a program would then run straight through for 50 minutes (or however long it was) without interruption—kind of like how PBS does it here. I remember wishing that the rest of our stations did it that way, too. Ever since, commercials have seemed that much more onerous to me.

Sure. It’s on my remote control. It is called the MUTE button, and to a certain degree, the Fast Forward button.

That ad filtering technology is alive, well, and readily available with a little research.

Thanks all for pointing out that this has already been done. I did not realize the technology has been around for so long. I did a Web search and found this Wikipedia article

This has been used in the pirating scene for a long time. I even use it at home. I have a HDHomerun with a OTA antenna hooked up to it. I use Plex to schedule recordings and when Plex finishes a recording it runs a script calling Comskip. That goes through and removes the commercials and re-encodes to a more manageable bitrate.