Long description
This figure is a screenshot from Signal Wizard. It shows two graphs, one labelled Time Waveform and one labelled Frequency Spectrum. The time waveform fluctuates randomly around a value of 0. Most of the time it stays in the range minus 0.25 to plus 0.25, only occasionally going outside this. The overall shape of the frequency spectrum is a line that remains at minus 40 for frequencies between 0 and approximately 3000, then drops gradually to minus 60 over the range of frequencies between 3000 and 5000, then drops sharply down to minus 100 at a frequency just above 5000. Again, it fluctuates randomly by a small amount around this line.