OK, I am in the midst of re-reading the Chamber of Secrets and something dawned on me. During the dueling club, everyone was able to hear Harry speaking Snake language right. But when Mrs. Norris is petrified, only harry can hear the snake. Of course he hears it in English, but why don't the trio, or anyone else for that matter hear the snake hissing in snake language? Surely, they can hear hisses?

I think that the snake was "talking" just loud enough so that any other snakes or parslemouths could hear it. Maybe it was just talking to Harry because it was taunting him or something. That's a very interesting question though. I'll have to think about that more.

There is also the possibility that they did hear it but mistook the sound for something else. Bear in mind that the basilisk was using the plumbing to move around the school. Now, I don't know what magical plumbing is like, but in a muggle equivalent of a place as old as Hogwarts, I've no doubt that the plumbing would make some pretty bizarre noises. The taps in my house are weird enough and that's probably 30 years old max.

I think everyone heard the basilisk but thought it was just the water pipes.

Maybe they heard the hissing and just mistook it for a background noise? There could be many eerie noises in a castle like Hogwarts, its stone halls and corridors amplifying some sounds. Or maybe the Parseltongue hissing was mistaken for ordinary plumbing sounds.

I have actually thought about this one before.the only thing i can think of is that they heard the hissing but it was too soft for them to really notice. Harry kept asking them if they heard the voice, and they didn't hear a clearly defined voice, like what Harry was describing.

well...that's a very confusing question not to mention it's very difficult too! i thought about it and i think a basilisk's voice can only be heard by people who can talk to snakes. it seems a very stupid theory but i can't think of anything else to say.

However, if they heard noises that sounded like the plumbing, would they think to mention it. If I'm asked if I've heard anything, I tend not to mention the everyday noises that surround me. It would be like saying "I didn't hear anything other than my own breathing and the blood rushing through my ears."

yes yes i beileve with potters girl i think that the snake was hissing loud enough for only other snake talkers could hear him

thats why ron and hermione were worried about harry they kinda thought that he kind of went mental on them (hehehe) that would be kinda scary to see "the boy who lived" turn mental

well ihope that cleard stuff up for you

i think that this is just a contuniancy error all writers of long novels about one fake world do have them.

No here is another idea WHAT HARRY HEARS IS ACCUALLY WHAT VOLDMEORT IS TELLING THE SNAKE

I wondered about the exact same thing, as well.
Firstly, there is always the possibility that it is a mistake. I don't know how likely that is, but it is always possible.

It is also possible that, like many others have said, it was just too soft for Ron and Hermione to really notice. I am not really sure about that, though.

It is possible that they just didn't say anything about it because Harry was talking about voices. They wouldn't hear voices. They would hear very soft hissing noises and wouldn't think much of it.

I think that the last one is the most likely of those three ideas. There is also a slight possibility that it will end up being significant in the end, but I doubt if it will be very significant. I think it is most likely that it is either a mistake or that they just heard soft hissing noises that could have been many things in a large castle full of wizards and witches being trained.

Very good question!

ehhh no.

Voldemort, at the time Harry was hearing voices, wasn't out of the diary yet. I'm pretty sure Riddle couldn't speak Parseltongue by means of a book. How about this - was it Ginny speaking Parseltongue? She maynot have conversed with the snake at all since she wasn't in the Chamber until she was almost dead.

No one hearing the hissing may just've been a mistake by Rowling.

I think the snake's hissing was so low that only the parseltongue speakers can notice that something is speaking around them.
Why did they hear Harry speaking parseltongue in the dueling club? Because Harry speaks more loudly than snakes because of He is costumary to speak in that volume in his original language.