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Published byBlanche Woods Modified over 9 years ago
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How Spread Works
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Spread Spread stands for Speech and Phoneme Recognition as Educational Aid for the Deaf and Hearing Impaired Children It is a game used to visually motivate deaf and hearing impaired children to learn to speak
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CLIENT How does Spread work? Record Selection SERVER Sphinx.wav file + current word Transcribe Scoring result Feedback
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CLIENT Selection SERVER
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Selection The user is presented with a screen showing the word to pronounce
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Selection The user is presented with a screen showing the word to pronounce
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Selection The user is presented with a screen showing the word to pronounce
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CLIENT Recording Record Selection SERVER
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Recording Recording begins once the user clicks the record button.
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CLIENT Transmission Record Selection SERVER.wav file + current word
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Transmission Transmission begins once the stop button is pressed. The wav file, the current word and the training phoneme are sent to the server for processing. transmission CLIENT K AA R SERVER Training Phoneme
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CLIENT Transcribing & Sphinx Record Selection SERVER Sphinx.wav file + current word Transcribe
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Transcribing Once the wav file arrives at the server, it is inputted into Sphinx in order to recognize what the user said Sphinx
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Sphinx is a Java-based Hidden Markov Model speech recognition system developed by Carnegie Mellon University Sphinx
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To decode the wav file, Sphinx needs three data sets – Acoustic Model – Dictionary – Language Model Sphinx Acoustic Model Dictionary Language Model
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Acoustic Model The Acoustic Model maps sound features to units of speech called phonemes Derived through the sampling of a large data set of spoken words called a speech corpus K AA R
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Dictionary The dictionary maps words into phonemes... CAN K AE N CAR K AA R CAT K AE T T...
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Language Model The language model indicates the probability of a particular word appearing given the previous words – Not used since Spread only needs to recognize individual words
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Decoding Sphinx in Spread is configured to detect what phonemes were pronounced by the user SPHINX K K AA R R
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Increasing Accuracy To increase accuracy, Sphinx in Spread is only made to recognize a limited number of phonemes per level 7 levels means 7 individually configured Sphinxes Sphinx Level1 CAR, JAR, STAR… Sphinx Level2 BED, NET, TENT… Sphinx Level3 PLAY, PARTY, CIRCLE…
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CLIENT Scoring Record Selection SERVER Sphinx.wav file + current word Transcribe Scoring
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The server compares the decoded result against the expected result, taking note of the training phoneme Sphinx You said: K AA R You said: K AA R Expected: Training Phoneme
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CLIENT Final result Record Selection SERVER Sphinx.wav file + current word Transcribe Scoring result Feedback
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The result is sent over to the client to give feedback to the user
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Preliminary results Tested with adult members of the hearing impaired community – Very positive. – "I wish I had this when I was learning speech" Problems: Too enthusiastic – Loud cheering noises reduced recognition rates
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Preliminary results SPREAD was tested with hearing impaired students of the SPED division of the Batino Elementary School in Proj. 3, Quezon City – Accuracy testing and software evaluation
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Working with the children Of the 40 students, only 5 volunteered to test the software – The children were generally shy and hesitant to perform the speech
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Working with the children The children only knew very few words – They knew how to sign some of the words but not to vocalize them General mood was as if they were taking an exam that they were not prepared for
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Working with the children Surprisingly, children were very good at conversational phrases – “Good morning” – “Good bye and thank you!”
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Working with the teachers Teachers still need to help the students vocalize some words – System at yet cannot be left unsupervised with the students
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Working with the teachers Noisy screen distracts students – Need to have a simpler screen to focus on
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Recognition Rates Sphinx recognition rates were low – Hampered by noisy environment
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Conclusion Need to work closely with SPED teachers on speech curriculum – Test on just recently learned words Conversational phrases – Hearing impaired children use simple phrases rather than words. – Conversational phrases spoken, other words signed UI improvements, simple is better Accuracy improvements urgently needed
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The Spread Team
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Image Sources Microphone - http://mmflc.com/images/microphone-stock-image.jpg Crystal Project - http://www.everaldo.com/crystal/ Wave form - http://bipinb.com/converting-wav-file-to-gsm-file.htm
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Extra slides follow…
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Scoring There are three possible outcomes – EXCELLENT – Good – Sorry
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Scoring Getting the training phoneme correctly as well as the correct length of the phoneme gets an EXCELLENT score K AA R Expected: Sphinx You said: K AA R You said: K AA R 3 Phonemes Long Got the Training Phoneme
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Scoring Note that Spread is only looking for the correct pronunciation of the training vowel K AA R Expected: Sphinx You said: K AA T You said: K AA T 3 Phonemes Long Got the Training Phoneme
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Scoring Not getting the correct word length gets a Good score K AA R Expected: Sphinx You said: K AA R T You said: K AA R T 3 Phonemes Long Got the Training Phoneme
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Scoring Not getting the training vowel means the user will have to try again – Length is no longer checked K AA R Expected: Sphinx You said: K AE R You said: K AE R 3 Phonemes Long Got the Training Phoneme Sorry =(
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Updates SPREAD has undergone BETA testing with a group of hearing impaired adults – Testing of original (pass/fail) algorithm Results – Low recognition rates even for recognizable speech – Puzzling due to high recognition rates with lab speech
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Recognition Rate WordRateClose word Apple60%Apple (60%) Art6%Bat (66%) Banana13%Apple(73%) Bat66%Bat (66%) Car0%Hand (46%) Fan0%Hand (53%) Hand20%Bat (33%) Jar0%Hand (60%) Lamb0%Apple (33%) Sofa0%Hand (46%) Star0%Fan (26%) Table0%Apple (46%) Van0%Art (26%) Wallet0%Hand (60%)
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Analysis Microphone Lab test data Live data
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Recommendations Better microphone/setup – Sphinx has preprocessing modules for less noise Per word recognition – Use creative word combinations to isolate training phoneme w/o having to go into per phoneme recognition Check out phoneme recognizers
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Per phoneme recognition Per phoneme recognition is worse – Spread is highly dependent on full words for increased recognition rates Recognizing: Lamb2.wav I heard: ae ah m Recognizing: Lamb3.wav I heard: ae m Recognizing: Sofa1.wav I heard: s ow l ow Recognizing: Sofa2.wav I heard: s ae Recognizing: Sofa3.wav I heard: s ow hh aa Recognizing: Star1.wav I heard: ao t Recognizing: Star2.wav I heard: s d aa r Recognizing: Star3.wav I heard: s d aa r Recognizing: Table1.wav I heard: ah d l Recognizing: Table2.wav I heard: ae ah Recognizing: Table3.wav I heard: ae ah Recognizing: Van1.wav I heard: m ae Recognizing: Van2.wav I heard: m ae
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