Many science textbooks (and government documents -- for example, that at contain a rather silly error -- the confusion and merging of audible and electromagnetic spectra.

Contrary to popular belief, the spectrum of electromagnetic radiation does NOT include an audible range of sonics, ultrasonics, and infrasonics. There is no reason to even mention such a thing on a chart of the electromagnetic spectrum. No matter how high pitched a sound one makes, it's still vibrations of air (or other media) molecules -- it'll never be a radio wave. No matter how low-frequency the radio wave is, it's still an electric and magnetic field -- it'll never be a sound.

No matter how high you scream, it's not going to come out blue.