[DECtalk] Some DECtalk history and what I think we can and can't reasonably do

jake mcmahan mcmahan.jake at gmail.com
Wed Aug 3 16:09:58 EDT 2011


On 8/3/2011 3:42 PM, ebruckert Bruckert wrote:
> Okay as an update listen to the to wave files separately not 
> back-and-forth listen to one we waited a few minutes listen to the 
> other. See if you agree were getting closer, one of course is what you 
> sent me
>
> On Wed, Aug 3, 2011 at 1:43 PM, ebruckert Bruckert 
> <edbruckert at gmail.com <mailto:edbruckert at gmail.com>> wrote:
>
>     agreed
>
>
>     On Wed, Aug 3, 2011 at 1:38 PM, Alex H. <linuxx64.bashsh at gmail.com
>     <mailto:linuxx64.bashsh at gmail.com>> wrote:
>
>         I, too, hope that HLsyn eventually will be a viable option and
>         we could use the old method or HLsyn if we wanted, maybe for
>         reading long texts and so on. It's a great idea and theory but
>         just isn't mature enough at this point.
>
>         Alex
>
>
>
>
>         On 8/3/2011 1:13 PM, ebruckert Bruckert wrote:
>>         There's always two sides to a coin, if DECtalk hadn't been
>>         purchased it would have died. And since there was no money
>>         from anyone to work on handicapped applications, we had to do
>>         what our customers want it or go home. I recognize that the
>>         HLsyn work did not yield the hoped-for results and perhaps
>>         someday it can with what we learned in our failures. But it
>>         was a decision based on the best knowledge we had at the time
>>         and in fact also with Dennis Klatt's work. The problems that
>>         occurred with the HL sin version aren't of any interest to me
>>         because the version put out was in early one and it's not the
>>         right time to pursue trying to perfect HLsyn. S
>>         On all I can do is my best.
>>            As to the person that mentioned the idea of putting
>>         meaning into the text. DECtalk actually has the ability to do
>>         some marketing and adjustment to train achieve that by hand.
>>         Automating the system to do that is deal beyond our knowledge
>>         and capability. Understanding what is being conveyed is
>>         extremely extremely difficult for a computer. A simple
>>         example;"You did that." Depending on which word you emphasize
>>         most there are three different ways of saying this very
>>         simple sentence with dramatically different meanings.
>>          Wed, Aug 3, 2011 at 12:07 PM, Alex H.
>>         <linuxx64.bashsh at gmail.com
>>         <mailto:linuxx64.bashsh at gmail.com>> wrote:
>>
>>             Well, to us,, we never really heard later versions of DT,
>>             only the classics from the 90's, so forgive us if we
>>             compare the new attempts to prior versions - it's not
>>             like we have a huge library of source code to just browse
>>             at will and endless samples of every version.... so... yeah.
>>
>>             Wanna know what's been wrong with the samples and
>>             attempts posted to this list a few months ago for the
>>             sapi dectalk? I'll tell you.
>>
>>             The voices were clipping and squawking, and all the
>>             voices sounded like they had a speech problem. Perfect
>>             Paul wasn't perfect as most of us have heard before. The
>>             voices themselves sound not like DECTalk at all, they
>>             also drop out in volume, just like a human cuz it's using
>>             HLsyn to make it sound more natural.
>>             I've heard DT 4.2cd, 4.3, 4.4, 4.61, 4.62 and 4.64. But
>>             since you've pointed out before that version numbers
>>             don't matter to speak, is this even important anyway or
>>             are we just listening to the same code with minor tweaks
>>             to get the various versions we know?
>>
>>             Disable HLsyn in the new product, and it'll suck less. I
>>             like forment based synths, not ones that try and sound
>>             human, because I and others are used to classic forment
>>             non-HLsyn versions of DECTalk. True that HLsyn is still
>>             formant but it's trying to sound real and have human
>>             articulation, and knowing that I can understand why this
>>             version sounds different. It's just not what we're used
>>             to, that's all. Some Joe Blow off the street who has
>>             never heard synthesized speech can't understand Eloquence
>>             from DECTalk from Espeak anyways, so this point of
>>             understanding speech is a moot one.  They'd be better off
>>             using Cepstral or some human-sampled synths and wasting
>>             their hard drive space. This is being targeted at a
>>             relatively small group of people who have used DECTalk
>>             before and like it, so i think we're safe there. I'd
>>             consider giving HLsyn another shot if it was completed.
>>             But as always, corporate America screws everyone over in
>>             the end, and that was the case with Dectalk. So much so,
>>             that Fonix wanted to make FonixTalk and specificly try
>>             and make it sound human. The result sucks.
>>
>>
>>             Alex
>>             On 8/3/2011 11:17 AM, ebruckert Bruckert wrote:
>>>                First of all let me make you aware that I use
>>>             DragonDictate, as I can't see very well and proofreading
>>>             is quite painful so you'll have to forgive and interpret
>>>             from mistakes the DragonDictate may make. It
>>>                I was taught about form and speech synthesis by
>>>             Dennis Klatt, and by reading but before my involvement
>>>             with him I knew next to nothing. One of the questions in
>>>             the early days was could you achieve higher
>>>             intelligibility by super articulation and do better than
>>>             natural speech. What testing revealed was really two
>>>             things. At normal speaking rates the answer always seem
>>>             to be that the closer you matched to real speech the
>>>             better the intelligibility at higher speaking rates
>>>             above that which humans could normally achieve things
>>>             were little different and I'm not going to go into the
>>>             specifics of what we did to make things better at high
>>>             speed other than to say they were based on knowledge of
>>>             speech perception.
>>>                  The second thing we learned is that listening to a
>>>             synthesizer has a very fast but steep learning curve.
>>>             Somewhat analogous to learning to understand a person
>>>             with a strong dialect or speech impediment. One of the
>>>             problems we encountered is that people often preferred
>>>             the version they were used to over any succeeding
>>>             version. But actual tests did not support the preference.
>>>                  One example is the way tilt was done inside
>>>             DECtalk. The original mechanism was a crude
>>>             approximation of spectral tilt. Dennis before he died
>>>             developed a much more accurate (meaning matching human
>>>             production) tilt filter that was not able to be
>>>             incorporated to a later date. As a point of interest
>>>             Dennis was so dedicated that he last modified the
>>>             DECtalk code 3 days before he passed away. So the
>>>             spectral tilt was changed and this changed what you
>>>             might consider the tone control on an old radio or
>>>             record player. That is just one of many reasons why
>>>             DECtalk change slightly over the years.
>>>                   The 5.0 DECtalk Incorporated the work of Prof. Ken
>>>             Stevens who was Dennis is blessed MIT and close friend.
>>>             The 5.0 code unfortunately did not yield the expected
>>>             results, but we did learn a lot from the attempt. This
>>>                    there are even some changes to DECtalk that would
>>>             change the way it sounds from any particular version,
>>>             such as Intonation that I am unwilling to revert because
>>>             I know for a fact that they caused loss of information.
>>>             So my goal is very simple I am working to create a very
>>>             functional intelligible DECtalk to put back out, I am
>>>             unwilling to try and make it sound exactly like any
>>>             given person wants to. I have been through this before
>>>             and the year is very sensitive and if you directly
>>>             comparing two versions side-by-side you not testing
>>>             anything but whether did the same and that is an
>>>             exercise in futility. T
>>>             Any specific issues I can address. Secondly as a word of
>>>             warning to listeners providing feedback. The other thing
>>>             we've learned is that listeners are excellent at
>>>             deciding that something is not right, but are absolutely
>>>             terrible at exactly pinpointing the problem. The reason
>>>             for this is quite simple people judge the output as
>>>             speech which it only kinda is, by this I mean that a
>>>             synthesizer can make mistakes that humans cannot
>>>             possibly do and as a consequence can't possibly
>>>             recognize. An example of this is that after so many
>>>             years of working with it I have learned to hear a
>>>             foreman that's moving too rapidly, but most people
>>>             cannot hear it. This is because to make life easy we try
>>>             to lead nor stuff that's not important in our language,
>>>             such as the nasal lifestyles in French or the retro flex
>>>             ours in American English which is Sheehan have a heckuva
>>>             time hearing.
>>>
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>>>             http://bluegrasspals.com/mailman/listinfo/dectalk
>>
>>
>>             -- 
>>             Sent via Thunderbird.
>>
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>>
>>
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>
>         -- 
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>
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Ed, good mighty lord, you're doing exelent dude.
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