        “There aren’t any that would work.”  Twilight looked at her surprised expression.  “In order to make a language spell work, the caster needs to know what language is being spoken, or else she needs to adapt a close spell in the field.”  She rolled her eyes upwards in thought.  “Let’s see, we covered this the year before I moved to Ponyville.  Language spells work by facilitating a limited connection from left inferior frontal gyrus of one pony to another and modeling the neural commands to the mouth, lips, throat, tongue, and larynx.”  Seeing the blank look in Lyra’s eyes, Twilight hastily simplified.  “If it’s a spell to allow speaking in a foreign language, it interrupts and changes the caster’s speech patterns, whereas for hearing it’s almost a telepathic work-around, although the more complicated spells do involve an aural aspect.”  She shrugged.  “It’s exceedingly complicated, and needs a very skilled caster to shift the spell to account for differences in regional accent, physiology, and neurological development.  It really requires a pair of creatures working together for some time to get it to function properly.  I’ve practiced a little with Spike, but he hasn’t really got the patience for it, and becomes embarrassed that his voice comes out sounding like a mare’s.”