<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:3.0cm 2.0cm 3.0cm 2.0cm;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=DA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span lang=EN-US>Hi,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>I am just having some interesting speculations about DECtalk, that I thought I would share <span style='color:#1F497D'>with the list</span>.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal>Have you ever heard Dennis Klatt’s collection of speech synthesizer recordings, that he maded in 1986?<o:p></o:p></p><p class=MsoNormal><span lang=EN-US>He made a collection of 36 different recordings of various speech synthesizers, detailing the history of speech synthesis, from 1939 to 1986, includin early recordings of DECtalk<span style='color:#1F497D'>, which was included in a paper in 1987, accompanying an article called “Review of text-to-speech conversion for English”</span>.<o:p></o:p></span></p><p class=MsoNormal>Here is a zip file with the entire collection:<o:p></o:p></p><p class=MsoNormal><a href="https://www.dropbox.com/s/4vtuhnrt8xvllkc/Dennis%20Klatt%27s%20speech%20synthesizer%20recordings.zip?dl=1">https://www.dropbox.com/s/4vtuhnrt8xvllkc/Dennis%20Klatt%27s%20speech%20synthesizer%20recordings.zip?dl=1</a><o:p></o:p></p><p class=MsoNormal>The recordings are in au format, but I think most programs are able to play them, otherwise let me know. I’ve included two different versions of the recordings. Version 1 has narration before each recording, detailing which synthesizer is recorded. Version 2 has no narration, but has slightly better audio quality. <span lang=EN-US style='color:#1F497D'>I am quite sure though, that the narration is not Dennis Klatt’s own voice, since the article states the following:</span><span lang=EN-US><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'>“thanks also go to Kenneth Stevens, who served as narrator.”<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal>So, listen to recording 33, of Klattalk, which formed the basis of DECtalk, and recording 35, which is of several of the DECtalk voices. Note that the Paul from Klattalk, recording 33, and Paul from DECtalk, recording 35, sounds almost, if not completely, identical, and also that they sound quite like the later DECtalk versions, like 4.2 and 4.3, not identical, but quite similar.<o:p></o:p></p><p class=MsoNormal>So, here I am asuming that the Klattalk recording is of the original system, while the DECtalk recording is of the current DECtalk version, as of november 1986.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>But then, listen to the three recordings in the following zip file, which is of DECtalk 1.8 and DECtalk 2.0, boath from 1984, and DECtalk 4.3 from 1996, reading the exact same text:<o:p></o:p></p><p class=MsoNormal><a href="https://www.dropbox.com/s/kbjrmoyhvig2of0/DECtalk%20Comparison.zip?dl=1">https://www.dropbox.com/s/kbjrmoyhvig2of0/DECtalk%20Comparison.zip?dl=1</a><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The thing that I find really interesting here is, that the Klattalk and DECtalk recordings from Dennis Klatt’s collection, to me atleast, sound much closer to DECtalk version 4.3 than version 1.8 or 2.0. You can obviously tell it’s the same voice in all the recordings, but to me, there is a difference boath in intonation and voice quality.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>So, what does this mean? For me, it raises a few interesting questions:<o:p></o:p></p><p class=MsoNormal>1: What ”DECtalk sound” came first?<o:p></o:p></p><p class=MsoNormal>If the Klattalk recording is of the original Klattalk system, then it must mean that DEC took that technology, made the voice sound quite different, and then changed it back later, all in a short period of time from about 1983 to 1986. Or, Dennis Klatt could just have used the current 1986 DECtalk version to make the Klattalk recording, which could mean that the original Klattalk, before DECtalk, sounded more like DECtalk 1.8 and 2.0. <span lang=EN-US>Another reference could be recording 32 from Klatt’s collection, the Speech Plus Prose<span style='color:#1F497D'> </span>2000 synthesizer. </span>Speech Plus also licensed Klatt’s work, like DEC did, but developed it in a different direction. <span lang=EN-US>It had only one voice, which was actually the voice Stephen Hawking used, and had a <span style='color:#1F497D'>quite </span>different intonation than DECtalk. This voice, to me, sounds <span style='color:#1F497D'>somewhere in between the DECtalk versions, but possibly </span>closer to DECtalk 1.8 and 2.0, which could emply that Klatt just used the 1986 DECtalk for the Klattalk recording.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal>2: What did Dennis Klatt’s own voice sound like, and how much was he involved with DEC’s development of DECtalk, after they licensed his work? Did his voice sound closer to DECtalk 1.8 or 2.0, or to the Klattalk and DECtalk recordings from his collection?<o:p></o:p></p><p class=MsoNormal>I haven’t been able to find any recordings of Klatt’s original voice on the internet, so I think this is really interesting. Personally, I find it most likely that his voice sounded more like the recordings in his collection, because they, to me, sound more human and naturalt han DECtalk 1.8 and 2.0. Also, that could explain why DECtalk 4.2, 4.3 and so on doesn’t sound that different from those recordings, because I suppose it would be difficult for DEC to continue to develop DECtalk to sound as close to his voice as possible, after his dead, unless they had several recordings of his own voice, which, of course, is possible. Another thing to consider is the ”Doctor Dennis” voice from DECtalk, which Klatt’s collection sadly hasn’t got a recording of. This voice was actually not available in DECtalk 1.8, but was included in DECtalk 2.0, but sounded extremely different from the later DECtalk versions. In DECtalk 2.0, the voice was very rough and the breathiness was way louder than the actual voice, while the DECtalk 4.3 version sounds very natural, with a clear, understandable voice, and just enough breathiness to make it sound nice, in my upinion. <span lang=EN-US style='color:#1F497D'>Here’s a zip file with a comparison of the two voices:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:#1F497D'><a href="https://www.dropbox.com/s/igmp977sra5nom8/Doctor%20Dennis%20Comparison.zip?dl=1">https://www.dropbox.com/s/igmp977sra5nom8/Doctor%20Dennis%20Comparison.zip?dl=1</a><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>I believe I read somewhere, that the Doctor Dennis voice was supposed to represent Klatt’s voice in later years, due to his illness breaking his voice, but then, it seems very strange that the later DECtalk versions would make the voice sound much better than the DECtalk 2.0 version, because I can’t imagine his voice got that much better before his dead in 1988.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Best regards:<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Aksel Christoffersen<o:p></o:p></span></p></div></body></html>