In this age, we are constantly surrounded by media of the electronic kind. Whether it is the Television at home, or the public announcement in the railway station. We hear it and see it, at almost all times. It is hard to escape the electronic media. However, we do not often wonder how does the audio visual system actually work in these types of gadgets? How does the television show the video and audio, and how does it show them in total sync. Here we will discuss how the audio visual system works at its many levels of complexity. For brevity's sake, we will keep it simple, but it should be noted that the actual system works with a lot more complexity, and it takes years of learning and experience to understand how it actually works.
First we will discuss the sound systems. The sound is produced in an loudspeaker by the vibration of a membrane, which is vibrated at precise intervals to produce the sound that we desire. Then, the problem of producing sound is that of giving that membrane an electrical signal of specific calibration. Once the electrical signal is given, the membrane will vibrate and produce sound. This way we can play a recording, and that recording is used to create an electrical signal, which is then passed on to the loudspeaker. The loudspeaker or any speaker, will respond to the electrical signal by creating the sound of precise duration. If we give the speaker an electrical signal of 10 seconds, it will keep on producing the sound for 10 seconds. This is how sound is produced - be passing on electrical signal in a one to one correspondence. In the computer systems, sound is stored in the format of .wav files, which are recordings of the intensity of the electrical signal at any time. So a song of 4 minute can be stored in a wave file, by recording its intensity for its duration. When we need to play that song, we can pass those intensity values to the external sound hardware, which can then play that sound on the computer speakers too.
Now we will discuss how video is created and displayed. Video is normally created in color. All the colors can be represented by the use of three basic colors red, blue and green. When something is recorded on camera, all the different intensities of that object are recorded. And when we want to display something, we have to then display all the given intensities of the three basic colors. That is how, if you look at your television screen minutely, you will see that it is made up of very small dots. And these dots are of three different colors - red, blue and green. These dots are either dimmed or brightened when we want to display something, and in this combination of display, we can see an object displayed on our tv screens.
Displaying the video and audio in an audio visual system simultaneously is not that complicated, and is accomplished by making sure that they remain in sync as they are both played at all times.