Frequency Analysis Window contains a graph of the frequencies at the insertion point (yellow arrow cursor) or at the center of a selection. This window "floats", meaning that you can click in the waveform on the main AVSAudioEditor window to update the analysis while the Frequency Analysis window is on top.
The information in this dialog is like one "slice" or line in the Spectral View of the waveform. The most prominent frequency is interpolated and displayed in a window below. You can move the mouse over the graph area to display the frequency and amplitude components of that frequency.
The Frequency Analysis window updates in real time while you play your file.
You can show or hide Frequency Analysis Window View/Frequency Analysis.