峰值幅度 (peak amplitude) 和均方根 (root mean square, RMS) 幅度是最常用的两种度量幅度的方式。
在比较两个幅度时，用两者之比通常要比用两者之差更好。为了让比较变得容易，我们经常用分贝 (decibel) 这一对数单位来表示幅度。 若信号的幅度为a (峰值或RMS), 则定义分贝 (dB) 级d为：
The most fundamental property of a digital audio signal is its amplitude.
The two most frequently used measures of amplitude are the peak amplitude, and the root mean square (RMS) amplitude.
Two amplitudes are often better compared using their ratio than their difference. To facilitate comparisons, we often express amplitudes in logarithmic units called decibels. If a is the amplitude of a signal (either peak or RMS), then we can define the decibel (dB) level d as:
(Source: Miller Puckette, The Theory and Technique of Electronic Music. World Scientific Publishing Co. Pte. Ltd. 2007)
The maximum deviation from the average or equilibrium value of any repeatedly changing quantity, such as the position of a vibrating object, pressure, velocity, voltage, current and many others. The amplitude of a sound wave is the maximum amount by which the instantaneous sound pressure differs from the ambient pressure. The variation of (maximum) amplitude over time is called the envelope of the sound. (Source: Barry Truax - Handbook for Acoustic Ecology CD-ROM Edition. Cambridge Street Publishing, 1999 - CSR-CDR 9901)
A technical term that describes loudness. The higher the amplitude of a sound wave, the louder it is.
The amplitude relates to the amount of displacement that the sound wave vibration exerts. Take care with sounds that have a high amplitude, loud sounds can damage your ears PERMANENTLY!
术语顾问/Consultant to terminology