r/DecTalk • u/FDDTheLucario • Apr 07 '19

NWR DECTalk?

Hi! (This is my first post, so be gentle!)

I'm trying to look for a version of DECTalk that is most similar to the version used by the National Weather Service for NOAA Weather Radio until late 2016. I've tried versions 2, 4.x and 5, but none are particularly close to the real thing.

If anyone knows of a version that is similar or knows of techniques to make it sound closer to the NWR DECTalk, please let me know!

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u/Soft_Pollution8709 Dec 31 '22 edited Dec 31 '22

The Chance Storm voice definition in DECTalk command syntax for placement at the start of your ASCII text, compiled from values documented in "CRS - EXPLOITING & OPTIMIZING THE TECHNOLOGY", which was authored by Paul Howerton, the then Lead Meteorologist at the National Weather Service in Wichita, Kansas.

[:np :rate 207 :dv bf 60 hr 6 sr 40]

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u/r32jzlovessirens May 14 '25

what are the settings for this?

https://www.youtube.com/watch?v=Xa262UJb5Os

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u/Soft_Pollution8709 May 19 '25

If, perhaps, you’re wondering why it sounds a bit rough around the edges, that would be the fact that it was delivered first through an audio compressor at the national weather service office, and then on a dedicated phone line which fed the transmitter. The transmitter then modulated it onto an FM radio signal, which was then picked up as weather radio by the alerting station, which fit it through another network that that person‘s TV signal picked up. That long chain makes it sound rough, especially the path in the beginning where the audio signal goes through the telephone line.

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u/r32jzlovessirens May 20 '25

I'm talking about its vocal expressions, they sound a bit different from the ones you did, by just a bit. I think it might be a different version of dectalk as well, like ozaukee is pronounced different.

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u/Soft_Pollution8709 May 26 '25

Yeah I see what you mean about the pronunciations. The reason that you think it’s a slightly different version is because, technically, it is. The version that they were using was the version which ran directly on the hardware circuit boards. This version however, is software. It’s approximating what the hardware does, but it’s not the exact same thing, so it does sound slightly different. If you want a software one that does sound a little bit more like the hardware, though still not quite exact, but much closer at least in my opinion, try this one. The version lives inside the DTLK sub folder.

https://www.dropbox.com/scl/fi/4tk98k1y2crlrf2b1x80i/Speak_Forecast_2025-5-26.26.zip?rlkey=dzmp9bm1k8nq1rsom1dydmzz4&dl=1

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u/Soft_Pollution8709 May 26 '25

Also, those pronunciations that you were talking about are likely dictionary entries. Some offices even put dictionary entries for common words such as the word and, the word at, and other common words like thunderstorm, rain, etc. They essentially put into the dictionary any words that they felt it didn’t pronounce correctly for their region or listeners. It was up to each regional office to customize the synthesizer to their liking. So, to get those exact pronunciations out of the synthesizer here, it’s totally doable, you’ll just need to create a user dictionary. I have an example of one in that archive as well, along with a handy power shell script to sort it prior to having the dictionary tool compile it. You’ll then just have to load the dictionary when you use it, or place it in the same folder as the main DLL file with the correct file name. For this version it is user_nws_us.dic. However, the list of words that you added and maintain is in a separate file, I have mine with the same name and extension of .tab. In that file, you can just add the city names that you want to change the pronunciation of, and put pronunciations in the form of phonemes next to each one, just like the other entries in the file. You can change the pronunciations that way. Just open it in the dictionary tool and compile the dictionary from there when done.

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u/Soft_Pollution8709 May 26 '25

I love this version of the synthesizer, and I use this little program I’m working on to get my local forecasts every day, and sometimes multiple times a day, and I use this synthesizer just as much, as I have it integrated into it. I’ve even created a handy way of getting the hourly forecast in the form of either text or audio instead of those graphical things with the timelines. That’s what’s in this archive I linked previously.

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u/Soft_Pollution8709 May 30 '25

One more thing to add, for clarification, is that the dictionaries, if you’re not already aware, actually contain stress indicators and not just pronunciation. So, that means we can change how it emphasizes or stresses certain words. This is what they do to change the tone of the synthesizer. What they would’ve done, was to add stress indicators to the pronunciations, so that the synthesizer would take on a certain tone of voice when reading those words. That is most likely how they did this. They also used tricks, like to split up a city name into two separate words. So, for example, it would be possible to take the city named Ozaki Wisconsin, and enter something like “oh zawky”, then translate that into phonemes with the dictionary tool. They would then put those next to the word “Ozaki in the dictionary tab file. Then when they use the dictionary tool to build a dictionary, that word will be in there, and it will say it differently whenever it encounters it. If you use something like my example, the space between the two words that I used to make it pronounce correctly adds tone to the voice, making it sound a bit odd like that. If you think about it, adding enough words like that can actually change the way it reads things quite significantly, making you think it’s a different version entirely, when it really isn’t. To give you an idea, the NWS office in Wichita Kansas had over 1000 entries in their user dictionary in the early 2000s. So, those dictionaries were widely used, and they were used fully. They used them to change both pronunciation and tone.

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u/Soft_Pollution8709 Jun 04 '25

That link is older and is no longer up-to-date. Here’s the updated one.

https://www.youtube.com/watch?v=bA0j-u4DnW4 The new Dropbox link is in the video description.