Our ears are built to listen to sound coming towards us from all angles. This sound is used by our bodies to even decode dimensions and distance as well as directional information.
The Good Old Days of Stereo
Traditional home theater setups included two speakers placed in front of us to the left and to the right to try and simulate all the complex special and directional data that we hear in a real world situation. For obvious reasons, there are limitations to this kind of setup. Early Bell Telephone scientists had concluded that it takes a minimum of 3 channels to covey reasonable simulation of a musical event – two channels at the left and right and one channel in the middle.
The Birth of Multi-Channel Sound
As the movie industry progressed here in North America during the 50's and 60's, audiences became more and more receptive to a multi-channel experience. What the movie industry found was that the more channels they added, the better the audience response and enjoyment. The more the visual experience is complimented by a real life experience, the more successful the end result. As a result, speakers were added behind the audience for the more ambient sounds and the left and right were used for music.
It is only in the last 10 years that home theater has been able to duplicate this in the living room to some extent and it is improving dramatically by the day now as technology advances and the cost of having this type of setup declines. The 1980's brought Dolby Surround, with four channels, and now we have Dolby Digital 5.1-channel sound on all newly released DVDs. That's six separate channels of sound: left and right front main channels (like stereo), a dedicated center channel speaker for dialogue to anchor the actor's voices at the TV screen no matter where you're sitting, two left and right surround speakers at the sides of your listening area for all those ambient environment sounds, and a sixth deep bass subwoofer channel. The subwoofer is the ".1" in 7.1--which contributes heavy bass effects such as thunder and vibration.
What Does the Future Hold?
So what is next? Well, there is another speaker coming for handling the height dimension of sound and now a further 'silent' speaker being added to the furniture so that the vibrations and interactivity is even more intense. The future holds many more exiting advances such as more extensive use of 3D technology to change the dimension which your sight experiences are based on. Smell is the only 'add-on' still not represented……but I am sure that is not far away too.
by: Peter Goldstein