USDOC Radio Frequency allocation table (http://www.ntia.doc.gov/files/ntia/publications/2003-allochrt.pdf) lists part of the radio spectrum as "Audible." Radio waves are electromagnetic (e.g. light), while audible waves are pressure waves in a medium (e.g. air.) They travel at very different speeds, and are very different things. We see one and hear the other (depending on the frequency.) An audible RF signal makes absolutely no sense to me. I wouldn't think a government document would get basic science so blatantly wrong, so i think i may be missing something here. If I Google "Audible VLF", there are a lot of hits on the subject. They seem to talk about something like receiving radio frequencies from lightning strikes, and playing them as audio. Or hearing buzzing in electrical lines. Neither scenario i would interpret as being an audible radio wave. What do you suppose the allocation chart is trying to say? Is it just wrong? Or perhaps correct, but misleading? Or am i completely missing something?