@nickyeow I made the English match the Japanese better. Is the Chinese still OK?

In that case if you want nickyeow to be warned, you should post on the chinese sentence :) for the moment an email warining is send only if you're the owner of the main sentence or if you has posted a comment on it

Yes, it's a problem with having comments related only to one of a set of linked sentences.

I've edited the Chinese sentence. Thanks for notifying!

Actually, it is dumb people who do. Not all deaf are dumb.

The japanese sentence specifies it's deaf and mute people who talk with sign language.
Just specify death make traductions kind of weird...

Yes, over one year later, this sentence is still as stupid as it was : Most deaf people don't use a sign language. Only dumb people use one...

I think I was hasty changing it last year. 聾唖 in Japanese mainly means "deaf-mute". As it says in 大辞林: "耳が聞こえず，話しことばが話せない状態。" I have now changed the English to "deaf-mute people", which is how 聾唖者 is usually translated.

The vast majority of deaf people, became deaf in their old age, so they heard perfectly well during all their life and learnt to speak normally. Once deaf, the ability to speak remains, so most deaf people, never need a sign language and continue to speak normally, even louder, since they don't hear anymore what they say. So a sign language is utterly useless to them.

Sign languages are necessary only to part of the people who are either dumb or deaf from birth or both.

Being deaf from birth doesn't necessarily implies the use of sign languages, since most deaf people are taught to speak using their voice even though they can't hear it. And they usually lip-read.

So, for deaf-born people, using a sign language is an option that not all of them retain.
Subsequently only for dumb people (ie people unable to speak either from birth or later in life because of an accident, a cancer, etc...) is a sign language a necessity to express themselves.

Non-deaf nor dumb people also learn sign languages to communicate with deaf people.