[lojban] Re: eSpeak and lojban

[Jonathan Duddington <jsd@clara.co.uk>]

On 09 Nov, Stephen Pollei <stephen.pollei@gmail.com> wrote:
> On 11/8/08, A. PIEKARSKI <totus@rogers.com> wrote:

> >  I just installed eSpeak and tried it out.  It is interesting, but
> >  has enough problems to limit its usefulness.

Hello, I'm the author of eSpeak.  But I don't know much about lojban.

The latest version (currently 1.39.23) is at:
http://espeak.sf.net/test/latest.html

> >  By the way, the thing that I found most awkward is the way it
> >  races through without pausing before the {ni'o}s.

There is a list of words in  dictsource/jbo_list  which have a pause
before them.  Since lojban doesn't use commas to indicate pauses and
clause boundaries, we must rely on words.  Please amend the list and
give me the updates.

This seems to be a problem with lojban, long sentences with no
punctuation.  How to know where to pause and where the intonation
should indicate end-of-clause.  Pauses and intonation are important to
indicate structure.  You can't read a long sentence out aloud without
pauses and intonation.

In the jbo_list file, you can specify for a word (or a phrase) that it
has a pause before or after the word, or that it has an end-of-clause
pause (which also changes the intonation).  With English and other
natural languages, eSpeak uses a pause before conjunctions such as
"and", "if", "which", and to indicate brackets and quotation marks. 
The end-of-clause pause is used for a comma or semicolon.

With lojban, it should be possible to determine the structure and
therefore where pauses should occur (but not by me, because I don't
know lojban).  Can this be done simply by associating pauses with
certain words? 

> I also have done very little as I'm not sure what to do about the x
> and z phomemes. I was completely stuck on those.

I've changed the sound of [x] phoneme recently, so try the latest
version.  You previously said that it was difficult to distinguish
between 'c', 's', 'z' (phonemes [S] [s] [z]).  These are the same
phoneme sounds which eSpeak uses for English and most other languages,
and I've not heard of any problem distinguishing them.  For example,
English "ship, sip, zip" sound distinct, as are "gash, gas, gaz". 
Perhaps the problem occurs with certain combinations of consonants? 

> I thought that adding the commas would help espeak pronounce syllable
> boundaries a little better; I haven't tested how espeak actually
> respondes to having commas all over the place.

What do you mean by "pronounce syllable boundaries correctly"?

> 1) get rid of { a } to { abu }, { e } to { ebu }, etc from jbo_list

This has been done.  eSpeak will only pronounce 'a','e','i','o','u' as
"abu" etc, if a program (such as a screen-reader) explicitly asks for
the letter name.

> 2) get rid of { m } to { my }, { l } to { ly } from jbo_list
> espeak shouldn't be touching any of the single consonants words, l,m,
> n, and r should be syllabics and according to at least some lojbanists
> should be valid cmevla.

Changed now.

>   { b } to { by } shouldn't really be that harmful . The cll would
> classify them as cmevla , but they aren't really made up of any
> syllables . I would prefer if they got altered to be { b } to { yb } ,

That's a simple change, when you decide.

> The upstream maintainer was reluctant to take a patch from me that got
> rid of them all, because he said some of the consonants would sound
> merely like a click noise; I think that is valid concern, but it
> should be the responsibility of the writer not to give bogus input to
> espeak.

Yes, but it's also the responsibility of eSpeak to try to pronounce
text even if it's not valid language.  A single lone letter is a common
typo error.

> 3) Get rid of the stuff which stresses cmavo from jbo_list but leave
> the upstream authors pausing in place . cmavo should never be stressed
> unless someone capitalized some of it's letters.

Are you sure?
"Stress" here doesn't mean "emphasized".  It just means that eSpeak
will give them the same stress as other words.  jbo_list contains a few
cmavo which are "not unstressed".  I don't know what they mean ("cai"
"cu'i", "pei" etc), but someone told me to include them because they
may carry more stress in normal speech than others.  

The important question is not, "is it strictly correct", but rather
"does it sound right" and "does it help intelligibility".

> It also will stress cmevla without capital letters which also isn't
> wrong really, it might even be the right thing to do according to some
> I've talked to. I'd prefer if it didn't stress cmevla  and leave that
> up to the writer, but I could be wrong about that. I request feedback.

Again, I think you misunderstand what eSpeak means here by "stress". 
It's just the normal stress on the penultimate syllable of most words. 
Not "special emphasis".  I think the lojban capital letter convention
is used when the stressed syllable is other than the default.  So no
capital letter means "stress on the penultimate syllable".

If there is a way in lojban text to indicate an emphasized word in a
sentence, then you can indicate that to eSpeak by using SSML (speech
synthesis markup language).


> maybe nice to have but dropped:
> 1)  in jbo_rules h, q, and w aren't really legal lojban characters,

They may occur in foreign names.
Accented characters such as 'ö' and ñ are not in the English alphabet,
but eSpeak should cope if it sees them.

> pause if they occur at the ends of a word ; y always needs pausing if
> it occurs at the end of words

> .. li'ertadji foreign word detection and
> fixup routines should handle the h,q,and w stuff even better than
> these espeak rules. The preproccesor also handles y stuff very well .

> 2) dj and tc but not ts and dz has special support in jbo_rules, my
> earlier patch had dropped that not sure if that's an improvement or
> not. Someone who knows better should figure out of affricitives are at
> their best.

The "dj" and "tc" sounds are nearly always considered as single
phonemes ([tS] and [dZ]) in other languages. "ts" and "dz" are often
not (eg. in English).  Listen for which sounds better.

> 3) Someone should check to see if the rules that change the sounds for
> l, n , r based on adjacent letters make sense. My earlier patch just
> made them more consistent.

> 4) Give extra pause to lo'u and le'u the error quote stuff and zo and
> zoi the regular quote stuff

I don't understand that one.

> I had also just ripped out some pausing stuff as the rules didn't
> really require them, and they don't hurt anything AFAIK.

Better to keep pauses if they help listening.  Human speakers need to
breath occasionally even if the semantics don't require it.

In English eSpeak, I put short pauses before words such as "if",
"which", "since", "as".

> Also I did nothing to change the x and the z,

What did you want to change?

> The critical fix is getting rid of the { .a } to { .abu } snafu.

Fixed since eSpeak 1.38

> Getting rid of the stressing of some cmavo 

Consider how they are spoken in real speech.

> and not adding "y" to single consonant cmevla would be nice,

I doubt it, if the consonant can't be a syllable by itself.

> but the x and z issue is more important, but sadly I don't think I
> can do anything about it.

I don't know what the problem is.

You wrote earlier that eSpeak is too fast.  Most blind users of other
languages say that eSpeak is too slow, even at its fastest speed!  But
with lojban, people are not native speakers and are not fluent.  Just
use a slower speed ( -s option if you are using the command line, or
the speed slider if you are using a GUI application).

Another idea is to add the following line to the end of the file
espeak-data/voices/jbo  (or if it's not there, then
espeak-data/voices/test/jbo):

words 1

That will speak words separately, not merged together.  The speech
won't flow as smoothly, but it's probably easier to listen to.  You can
use larger values in the range 1 to 4 to give longer gaps between words.



To unsubscribe from this list, send mail to lojban-list-request@lojban.org
with the subject unsubscribe, or go to http://www.lojban.org/lsg2/, or if
you're really stuck, send mail to secretary@lojban.org for help.