You know, I have asked myself the same thing. It is not popular with advertisers so it never will be marketed. Just as the vcr,s that automatically could skip commercials while recording were banned. It is a simple device, your camcorder camera has one for the mic. You can record crickets and other backround sounds at night and the device will amplify the recording, but when a dog barking or loud sound is around, you will notice the backround noises gone because now the device is damping the sound so when you play the recording, it all sound at the same level. I believe the parts are about tens dollars at radioshack. If I new how to build it, I would. Edit: I wanted to add if anyone has rented movies that when the soundtrack is only music, it is so much louder than the voices. So I turn it down and when the music is finished and voices are back, you can barely hear hear the voices. About this device, I found if I play the movie through the computer, it has a automatic gain control if needed. It worked very well to keep noise and even level. I wish I could get one to splice between the speaker and source. A very simple job.

I used to have a Zenith television that would normalize the volume during commercials. With my new TV I am reaching for the remote every 6 or 7 minutes. It should be illegal to raise the sound volume of commercials.

Some TV's have an AVL (automatic volume level) control which normalises sound levels so the TV can be playing a mouse sueaking or a jet taking off and they sound the same volume level, likewise with adverts.

Yes, there are many such products on the market, and more/better ones are coming out all the time.

hello, i hve something called the "mute button".i just click it once and poof,no sound.

not that i know of