[DECtalk] DECtalk TTS licensing

[Don]

On 8/30/2021 9:21 AM, Karen Lewellen wrote:
> Please do not  stand in the way of another person's desire to add choices to
> the marketplace, because your chosen tool works for you.
> I can say with firm certainty, as I am using Dectalk to write this email, that
> there are loads of others who would welcome choices, espeake is not even a
> worth while consideration.

The world of synthesizers doesn't contain JUST two offerings!
If you are a consumer, your offerings are limited by those that
will "drop in" to your environment.

But, as a developer, you can build on any number of offerings,
with or without proper "licensing".

> To answer the question starting this thread.
> Last fall I sought to learn myself who  held dectalk Patents.

There are two issues involved:  patents and copyright.  Purchasing
a license, in theory, addresses both of these issues.

Copyright can be avoided simply by not *copying* the existing
implementation.

Patents are a tougher beast.  If, for example, there is a patent
that makes an independent claim of "presenting textual content via
a TTS conversion algorithm", then it won't matter who's synthesizer
you use -- the patent will be infringed.

Often, one can buy IP outright for very low dollars -- especially if
the current owner has little interest in the product.  When you consider
the burdened costs of developing "from scratch", a man-year translates
into ~$200K -- neglecting "opportunity costs".

OTOH, if your goal is to substantially alter/improve on an implementation,
then the (source) license may not be worth as much -- it may impose
constraints on how much you can alter the codebase, it may require you
to make your improvements available to the original owner as part of
the deal, or the existing implementation may just be inappropriate to
modify to your new goals.

> My first search, dectalk speech synthesis produced a Wikipedia page that
> tracked part of the  path, leading to a company in the  United Kingdom who did
> answer e-mails, actually providing licensing rates.

Note that there have been many other "open" implementations of DECtalk-alikes,
over the years.  And, you can walk backwards (in time) to see Klatt's original
work at MIT -- much of which is published or available if you scrounge around.

This approach also gives you insight into the technology.  So, you understand
all of the tradeoffs, the sorts of things that can go wrong in a "translation",
etc.

> Now, I am not absolutely sure if they hold the United states authorizations.
> If you write me privately though I will share what I learned with you.