Channel Phase vs Time #

View Channel Phase vs Time
(Forensics version only) #

A useful “cousin” plot of the X-Y averaging display is the “View Channel Phase vs Time” function found under the Forensics menu. We recommend reading the section on the X-Y plotter to help gain some insight into all channel phase related phenomenon before using this feature. The channel phase vs time routine plots the average phase angle between the two audio channels vs time which can be useful in Forensics authentication applications. The vertical axis (Y) represents the average phase between two audio channels (with a span from 0 to 90 degrees) while the horizontal (X) axis represents time. The middle of the Y axis represents an average phase angle of 45 degrees. The intensity (Z Axis) of the green graph line is intensity modulated as a function of signal magnitude. This system requires a two–channel signal to perform its function and will not function with single channel signals. This plot overlies (on top of) the spectrogram and is shown via a green line. Sometimes, it may be found to be useful to bring up the X-Y plotter (View Menu) while using this tool since it also shows the instantaneous phase of the two audio channels thereby giving you additional information about the file being investigated.