okay, i am really reaching here, so this is just a guess. but i was in this osteology of reptiles seminar, and in know that many reptiles (especially, it's thought, a bunch of dinosaurs) hear through vibrations in their lower jaw. now, i am guessing that leos probably have additional auditory equipment, just because of those huge ear holes (to use a scientific term, hehe). anyways, so i think the proximity of the leos to the sound is more the problem, just because of vibrations carrying, especially through solid structures (like a desk). but i know i have cranked it up (as much as one can in an apartment complex), and my leos, at the other side of a large room, are distinctly not bothered. though my ferret hates it, hehe.
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marla
keeper of: axolotls, catfish, ferrets, leopard geckoes, oriental fire-bellied toads, and sugar gliders