Using digital techniques, the capability to process information is greatly enhanced.
The design nature of audio recording, signal processing, and reproducing hardware has followed the advance of digital technology; the introduction of software programming into the practical audio environment has been simply revolutionary.
The distance above or below the centerline of a waveform represents the amplitude level of that signal.
The greater the distance or displacement from that centerline, the more intense the pressure variation, electrical signal level, or physical displacement will be within a medium.
Waveform amplitudes can be measured in several ways (Figure). For example, the measurement of either the maximum positive or negative signal level of a wave is called its peak amplitude value (or peak value).
Graph of a sine wave showing the various ways to measure amplitude.
Time relationship between two or more sound wave at a given point in their cycles.
eg: Whenever two waveforms having the same frequency, shape, and peak amplitude are completely in phase (meaning that they have no relative time difference), the newly combined waveform will have the same frequency, phase, and shape...but will be double in amplitude (Figure).
The amplitudes of in-phase waves increase in level when mixed together.
The process of converting from analogue sound to digital sound is performed by the Analogue-to Digital Converter (ADC) and later the re-conversion back to analogue sound from digital sound is performed by the Digital-to-Analogue Converter (DAC).