Add an extra button to the television remote that says 'detach/attach sound'. When you go channel surfing, you can push 'detach sound'. The sound of the channel you are on will stay, the picture changes with those of other channels. When you push the button again, it will attach the sound of the channel
you are on. If that was a mistake you can push it again and the sound goes back to the one from the channel you started off with.
This allows a more natural way of 'looking around'. Compare it to a cocktail party. In the distance you see people you would like to talk to. But you can not hear them yet, first you have to go over there. You can also just stay put and 'scan the room' to see where else you would like to go to. If you do not like what you see as alternatives, you do not move.
The same with television. You are on some channel, but you are curious to look around on the other channels to see what is going on. When you start zapping, you are displaced from your 'home base'. You are warped into other tele-presences completely, while you are cut off from your starting point. After flying around (with) both your senses you land on some other channel. This is quite disruptive, because you did not really want to leave your channel, you were just curious to see what is on the other channels. Just looking around, not flying around through the room. With this new feature you can just look around.
It should cost television manufacturers only a few euros to change the circuitry in the television and add a button on the remote. The tuner should separate the tuning to sound and image and have those two treated differently instead of bundling them always. When buying a new tv-set, such a feature that costs nearly nothing, but greatly enhances the zapping experience, will be convincing when choosing between two sets that are similar in features and price except for this. One might even want to sacrifice other features for it.
If this catches on, the content of television will change. It will become more important to make the image more appealing. The shouting and sound-bites will decrease because the viewer will stick to the channel with pleasant storytelling. Sound will then serve to retain the viewer to the channel, while the image will be to attract. Sound on television is now abused in order to _attract_ viewers. "Stay tuned! after the break we will continue with this compelling story!" Similar to the cocktail party experience, you turn away from people who shout, but will not think of leaving the company of someone who is telling a compelling story. No matter how beautiful the people are you see entering the room. They can wait, you have seen them, that is sufficient for the moment. Perhaps later we talk.
It will also be possible to start commenting on other channels. For example an alternative comment on a big soccer match on another channel. Or some local public access channel has some kids doing hilarious dubbing to the president giving a press conference on a national news channel. If it is done live and they are good at it, it will be popular. You might also want to mix watching two movies and see what happens.
Now I hear you say "we already had Picture In Picture (PIP) which did not catch on." It did not, because it is conceptually too difficult for daily usage. You have to 'manage' two pictures at the same time. You can only look at one thing at a time, so you find yourself either looking at the picture you were already watching (and the PIP is just as annoying as an animated logo of a tv-station) or you start looking at what is in the PIP and you quickly zap to that channel. The PIP is merely a transition stage before zapping to the other channel. We do not need such a in between stage. It is strange to say that there is currently a high threshold for viewers to zap to another channel. Quite the contrary, we zap easily to another channel. We just tend to forget what we started off with watching.