Because the native language of the deaf is sign language. Spoken language has very little in common with sign language. Text is a written form of a spoken language for those who hear so it isn't too hard to learn. For someone who can't hear it is completely different from anything.

Imagine the time where you knew something of a second language, but were not fluent yet (some of you may have never tried, but most people have done at least a little of a foreign language), watching a program in that language with subtitles in that language. That is what text subtitles are for a lot of deaf.

I imagine it would be like if your native language was English, but learning to read and write would all be in Cantonese instead.

It's faster to read text than to listen to someone speak, yet speech remains popular. There are aspects of communication which are not easily replicated in text -- sign languages do not lack the semantic information that is provided in speech by the tone, pitch, and rhythm of voice which is not, for the most part, reflected directly in grammar (in English, anyways). These components take other forms (expression and aspect, primarily) in ASL.

> It's faster to read text than to listen to someone speak, yet speech remains popular.

I suspect there are a few reason for that beyond the explanations you gave.

1) Speech is faster to produce than text. Professional captioners are among the few who can challenge that. For everyone else, it's usually faster to give a speech or say what's on your mind than to type it all out.

2) Speech frees up the eyes. My vision is usually in greater demand than my hearing, so I prefer to avoid committing it to a single activity for a long time if possible. Unfortunately, that's not an option for those without hearing.

3) Speech is easier to attribute to individuals. I can determine who said something with minimal effort just by listening to the sound of their voice.

4) Speech is more immersive for narrative content. Movies and TV shows feel more believable when characters are talking with each other face-to-face like they would in real life.

Unfortunately, a signer in the corner can't make up for any of those factors.

I think these are reasonable. I should highlight, though, that 1, 3 and 4 are true for sign languages as well -- 3 and 4 doubly so (given how large a component individual expressions and gestures play in communication without sound).

> 1, 3 and 4 are true for sign languages as well

That's true so long as the speaker is the one signing, which is probably true in the context of video calls but probably not in the context of TV.

I believe 4 is. At least, in the sense that intent, rhythm and emotion can be conveyed by a signing translator better than text can.

I've specifically heard from a deaf person that they much prefer a sign interpreter over captions because the sign interpreter can convey nuance and mood more reliably than captioning.

A few reasons: 1) You loose facial expression communication 2) Its slower to digest (small/slow text scrolling across bottom of screen) 3) Its harder to learn to read as the process is aided by phonetics

The simple answer is that language can't be captured in text alone.

Think of how expressive language is. You can say the same sentence 3 different ways, where the real meaning is trapped in the tone, intonation, pitch, and emotion.

Think of how dynamic and expressive the word "fuck" is... Probably the most versatile and complex word in the English language.

Or just look at the [national anthem](https://www.today.com/popculture/asl-performer-steals-show-d...)

> _Why use sign language on platforms where text is accessible?_

I'm not an expert, but I suppose that text is a foreign language to those born deaf. They might prefer to communicate in their native language.

(But if someone has lost their hearing after learning to read and write, then it would be different.)

Sign languages can convey information more compactly than a textual description. Objects can be given spatial relations that requires (relatively) elaborate descriptions with text.

Asl is actually a diff language than English. Surprisingly, ma y ppl can understand the asl but not the textual English. For many people English is a 2nd language they understand less well than asl.

Because I have gone to see films in a number of languages I do not understand but they were sub-titled. I can't remember going to one that was not anime, and then not hearing someone complaining about having to read the dialogue.

These films (Chinese, Korean, Japanese, French and German) all clearly had posters at the theaters saying they were sub-titles and yet there was always someone demanding the movie be in English.

Also I think a number of people have poor/slow reading skills that they can't bluff about when someone uses signing.

Closed captions aren't universally available, and live captions are often pretty awful (captions for recorded content are often fairly awful).

I recall seeing interpretters on TV during special broadcasts a lot, but then they were mostly replaced by open captions or (presumably) closed captions as captioning became generally available. I'd guess there's a bigger pool of skilled captioners than skilled interpretters, but it's also a lot easier to find someone on staff who can type fast to caption in a pinch.

All that said, I do see some very special events with interpretters still, and I apprechiate that, even though I don't sign.

1. The captions usually suck 2. Would you mind if they just shut off the audio?

As someone who watches subbed TV and movies frequently, it wouldn't particularly bother me. I prefer audio in my native language so I have the luxury of being able to take my eyes off the screen for a moment now and then, but that's not really an option when it comes to sign language.

That's a good point! Sign Language is the native language for Deaf People, not English Text.

In addition to what others have said, text encodes oral language well but is not necessarily a good fit for sign languages. I guess it might be like writing a non-Latin scripted language using Latin letters?

Many people who rely on ASL are illiterate. Turns out a phonetic portrayal of language they don't know isn't the easiest to learn, assuming they have the support to do it. Sign language exists because it is the best tool for the job.

http://www.deaf-culture-online.com/aslnotguilty.html

For the same reasons people choose to use audio on platforms where text is available.