HOW AUDIO WORKS IN COMPUTER
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Audio is a acoustic sounds, usually used to create a music. Audio frequency (AF) of a signal conveying the sound and synchronizing pulses in a radio broadcasting system. An audio frequency is an electrical alternating current within the 20 to 20,000 hertz range that can be used to produce acoustic sounds.
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Audio are generally referred to as signals that are audible to humans. Audio signals usually come from a sound source which vibrates in the audible frequency range. The vibrations push the air to form pressure waves that travels at about 340 meters per second. Our inner ears can receive these pressure signals and send them to our brain for further recognition.
How Audio Captured Work
A sound system operates by converting sound waves into electrical energy, increasing the power of the electrical energy using electronic circuitry, and then converting this resultant electrical energy back into physical energy in the form of sound waves.
Working with audio means working with sound systems. Naturally, the range of systems available for different applications is enormous. However, all electronic audio systems are based around one very simple concept: To take sound waves, convert them into an electric current and manipulate them as desired, then convert them back into sound waves.
A very simple sound system is shown in the diagram below. It is made up of two types of component:
Transducer • A device which converts energy from one form into another. The two common types of transducers:
Microphones • convert acoustical energy into electrical energy. Speakers - convert electrical energy into acoustical energy.
Amplifier • A device which takes a signal and increases its power.
The process begins with a sound source, which creates waves of sound. These waves are detected by a transducer, which converts them to electrical energy. The electrical signal from the microphone is very weak, and must be fed to an amplifier before anything serious can be done with it. The loudspeaker converts the electrical signal back into sound waves, which are heard by human ears.
The next diagram shows a slightly more elaborate system, which includes:
Signal processors • devices and software which allow the manipulation of the signal in various ways. The most common processors are tonal adjusters such as bass and treble controls.
Record and playback section • devices which convert a signal to a storage format for later reproduction. Recorders are available in many different forms, including magnetic tape, optical disc, computer hard drive, etc.
The audio signal from the transducer is passed through one or more processing units, which prepare it for recording. The signal is fed to a recording device for storage. The stored signal is played back and fed to more processors. The signal is amplified and fed to a loudspeaker.
Three Part Audio Model
One simple way of visualising any audio system is by dividing it up into three sections: the source, processor and output.
Source • is where the electronic audio signal is generated. This could be a live source such as a microphone or electric musical instrument, or a playback source such as a tape deck or disc.
Processing section • is where the signal is manipulated. For our purposes, we will include the amplifiers in this section.
Output section • is where the signal is converted into sound waves, so that it can be heard by humans.
