Logarithmic Frequency response graphs

Because in order to show the same results on a linear scale, the page would have to be 10 feet wide.

Because there are twice as many frequency/cycles for every octive and the graph repeats every decade so that it is readable. I believe this is a semi-logarithmic graph as the vertical scale is linear.

Human hearing is also perceived in a logarithmic scale.

Thanks for the responses. Let me re-phrase the question a little more specifically.

Why do I usually see freq. response graphed logaritmically between octaves while the ocataves themselves are spaces linearly?

Duddley...A Logarithmic scale shows DECADES equally spaced...100, 1000, 10,000 etc. Octaves would be 20, 40, 80, 160, etc.

A Log scale is used when the quantity being plotted behaves in a Logarithmic way. If you plot such a quantity on a linear scale and you pick the scale so that it is appropriate for one end of the range, the other end will be all scrunched up or stretched out, so that it cant't be read. (Take one of your Log scale plots and try to plot it on a linear scale).

If one axis is linear, and the other is logarithmic, the plot is called "Log/Linear".