10.6

703Logic Pro Instruments
Other waveform properties
In addition to frequency, other properties of sound waves include amplitude, wavelength,
period, and phase.
• Amplitude: The amplitude of a waveform indicates the amount of air pressure change. It
can be measured as the maximum vertical distance from zero air pressure, or “silence”
(shown as a horizontal line at 0dB in the illustration). Put another way, amplitude is the
distance between the horizontal axis and the top of the waveform peak, or the bottom
of the waveform trough.
• Wavelength: The wavelength is the distance between repeating cycles of a waveform of
a given frequency. The higher the frequency, the shorter the wavelength.
• Period: The wave period is the amount of time it takes to complete one full revolution of
a waveform cycle. The higher and faster the frequency, the shorter the wave period.
• Phase: Phase compares the timing between waveforms and is measured in degrees—
from 0 to 360.
When two waveforms begin at the same time, they are said to be in phase or phase-
aligned. When a waveform is slightly delayed in comparison to another waveform, the
waveforms are said to be out of phase.
Note: It is difficult to discern a constant phase difference over the entire wave period,
but if the phase of one of the waveforms changes over time, it becomes audible. This is
what happens in common audio effects such as flanging and phase shifting.