Hi,
I am the one responsible for the recognizer and tone models.
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Detailed instructions for anyone who still hasn't got it working, and skinkie if he wants to copy and paste it to the programs webpage.
Find the /speakgoodchinese folder
Right click on the sgc.bat file
Properties
Options
Set current code page to United States.
I have put this workaround on the download page.
http://www.speakgood...g/download.html
Thanks
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Does the program test absolute levels as well as relative levels? That is, does it test that my 2nd tone rises high enough or that my 4th tone falls low enough? Or is it testing that my 4th tone falls enough relative to the starting point?
Yes. SGC compares the overall pitch (top) of the correct tone model to the pitch of the utterance. If the test utterance is more than 3 semitones below or 6 semitones above the model tones, it is discarded. Then the ranges of the tones (rises/falls) are compared. With the same cut-offs. Only then is the tone recognized. The recognizer too does use the shape and extend of the rises and falls.
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I read somewhere in the documentation that the program is generous with regards to giving correct responses so as not to discourage new learners. In future versions it would be helpful if the user could choose the tolerance level.
Actually, you can by setting switches in the scripts. But you wouldn't want to.
The short reason is, the student should get the benefit of the doubt. A longer reason is that the recognizer type (Dynamic Time Warping on model contours) is much more likely to falsely reject a correct tone than to falsely accept an incorrect tone.
We managed to get both equal (the optimum solution) at around 15% for actual use data. This error rate is rather high for single bi-syllabic words, but building recognizers for beginning language learners is still an unsolved problem (for read "typical words" by native speakers we got below 5%, a meaningless statistics).
The tuning is done in two ways. First, SGC will pick the correct tone if it is close enough to the best (incorrect) solution. Second, many confusions which are part of Mandarin assimilations tend to remove the differences between tones in certain contexts (eg, tones 2 and 3 in the context of another 2 or 3). We just consider the utterance correct if the recognizer picks the wrong tone of a confusionable pair (eg, if 2-3 is recognized as 2-2).
These rules can be found in SpeakGoodChinese/SGC_ToneProt/SGC_ToneProt.praat
Look for:
# Special cases
However, if someone knows more about chinese tone assimilation/coarticulation phenomena, please feel free to point out our mistakes. We really are NOT well informed in the phonetics of Mandarin. Especially the neutral tone proved to be an enigma (however, we alread contacted Yiya Chen).
Btw, we also worked on a pronunciation recognizer. That proved to be much more difficult and the end result was so bad and the project time so short that we stopped that. It is still open to development, though.
Rob van Son