Logarithmic Scale Question
The meaning of the logarithmic plot is that the signal power above 250 Hz is about ${10^{-10}}$ times less that the starting values (most of the power is concentrated at the lowest frequencies), so it's almost zero. The capability of a logarithmic plot is to show both, the high and low values at the same time, specially useful in acoustic field. The negative aspect is the visual distortion of the signal, you must always keep in mind that what are you looking at is a logarithmic plot.