Disclaimer: I had written it while playing a Harry Potter RPG - please don't take it too seriously !

What exactly is Parseltongue?

At first glance, it seems to be just another animal language, similar to the "dogs' language", "cats' language", etc. However, in one important respect snakes are different from most of the other animals - according to the common knowledge, snakes are deaf ! They simply do not have ears, so the only sounds they can detect are low-frequency earth vibrations, received by their belly muscles (from other sources -- by their jaws) and transmitted to their inner ears. Snakes can hear other creatures approaching, but they can't hear them talking !

However, the latest research shows that the old theory about snakes' hearing is wrong. Many scientists now agree that snakes CAN hear, at least as well as lizards. The skin and muscle tissue on each side of a snake's head covers a loosely suspended bone, called the quadrate, which serves as an equivalent of ear - it moves in response to airborne sounds, and this movement is transferred to the inner ear, which, in its turn, produces electrical signals, transferred to the brain and analysed as sounds. Most snakes can hear a person speaking in a normal tone of voice in a quiet room at a distance of about 10 feet (3 m).

So Parseltongue indeed might be snakes' spoken language - but there are some facts about it that prove otherwise. My hypothesis: Parseltongue is telepathy. Here is why:

  1. According to the Harry Potter books, one can't learn Parseltongue - one has to have this ability from birth, or, at least, it must be acquired in a "magical" way (like Harry Potter, who apparently got the Parseltongue ability from Voldemort) This is not the case with any "real" languages, which are possible to learn, no matter how difficult. However the "extrasensory" human abilities like telepathy are very likely to be inherited, and not learnable. This kind of ability can also be dormant for years, and then suddenly manifest itself. Remember the first book, when Harry talked with the boa in the Zoo - he suddenly found out that he could communicate with the snake, without any training or lessons. It never happens even with people who are very gifted with foreign languages.

  2. Whenever Harry talks to snakes or listens to them, his impression is that he is speaking or hearing English. It is very characteristic of telepathy! Although some forms of telepathy might not be language-based at all and transmit the basic "concepts" or emotions, humans do think in words, and if they telepathically receive any "spoken" information, it is natural that the brain automatically translates it into their mother tongue. (Otherwise there would not be too much sense in telepathy - it could exist only between the people who speak the same language, and from what we know about the telepathy, this is not the case.) If Parseltongue were not telepathic, there could be no explanation of Harry perceiving it as English - no matter how adept a person is in a foreign language, he can't mistake it for his mother tongue.

  3. Both snakes' and humans' hearing ability is limited - however, in book 2 Harry was able to hear the Basilisk from everywhere in the school, and in book 4, Voldemort called Nagini, who had been wandering somewhere in the Riddle's mansion, and she came. One might argue that the Basilisk could've been following Harry around (inside the wall pipes), and Nagini could hear Voldemort from afar, because she had an unusually keen (for snakes) sense of hearing. But telepathy explains it much easier - it is not nearly as restrictive as spoken communication, and telepathic contacts can be established over much bigger distance than inside the same house (even a very big house!)

One fact doesn't exactly fit the telepathy theory - whenever people speak in Parseltongue, they appear to be hissing, and if the communication is not audible, there doesn't seem to be any need for hissing. A possible explanation is that hissing helps humans to concentrate, kind of puts their brains on the right "frequency", the same way some people move their lips when reading to themselves.

I hope it is enough evidence to confirm the telepathic nature of the unique snake language called Parseltongue !