Digital Signal Processing Reference
In-Depth Information
Chapter- 1
Audio Signal Processing
Audio signal processing
, sometimes referred to as
audio processing
, is the intentional
alteration of auditory signals, or sound. As audio signals may be electronically
represented in either digital or analog format, signal processing may occur in either
domain. Analog processors operate directly on the electrical signal, while digital
processors operate mathematically on the digital representation of that signal.
History
Audio processing was necessary for early radio broadcasting -- as there were many
problems with studio to transmitter links.
Analog signals
An analog representation is usually a continuous, non-discrete, electrical; a voltage level
represents the air pressure waveform of the sound.
Digital signals
A digital representation expresses the pressure wave-form as a sequence of symbols,
usually binary numbers. This permits signal processing using digital circuits such as
microprocessors and computers. Although such a conversion can be prone to loss, most
modern audio systems use this approach as the techniques of digital signal processing are
much more powerful and efficient than analog domain signal processing.
Application areas
Processing methods and application areas include storage, level compression, data
compression, transmission, enhancement (e.g., equalization, filtering, noise cancellation,
echo or reverb removal or addition, etc.)
Audio Broadcasting
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