專題研究語音訊號處理專題

助教：余典翰指導教授：李琳山

2013/07/30

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Outline

• Acoustics (聲學 )

• Phonetics (語音學 )

• Useful Tools

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AcousticsPart 1

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Acoustics (1/4)

• Oscillogram(波形圖 )

• Spectrogram (頻譜圖 )

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Acoustics (2/4)

• Frequency– hertz (Hz)

• Amplitude– decibel (dB)

• Phase– degree (∘)

period amplitude

𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦=1

𝑝𝑒𝑟𝑖𝑜𝑑

phase

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Acoustics (3/4)

• F0 (fundamental frequency 基頻 )– property of vocal fold (聲帶 )vibration– pitch (音高 )

fundamental period

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Acoustics (4/4)

• F1, F2, F3… (formant frequencies 共振頻率 )– properties of vocal tract (聲道 )– phone (音素 )

F3F2

F1

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PhoneticsPart 2

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Phonetics (1/4)

• Transcription–語音符號

• Articulatory phonetics (speech production)–語音發聲

• Acoustics phonetics–語音聲學

• Auditory phonetics (speech perception)–語音聽覺

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Phonetics (2/4)

• Vowels– Monophthong (單母音 )– Diphthong (雙母音 )

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Phonetics (3/4)

• Consonants– Voiced (濁音 )– Unvoiced (清音 )

╳– Plosive/Stop (爆破音 /塞音 )– Fricative (擦音 )– Affricate (塞擦音 )– Nasal (鼻音 )

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Phonetics (4/4)

• IPA consonants for English

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Useful ToolsPart 3

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Useful Tools

• Praat– http://www.fon.hum.uva.nl/praat/

• Wavesurfer– http://www.speech.kth.se/wavesurfer/index.html

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Praat (1/6)

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Praat (2/6)

• Read from file (.wav)

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Praat (3/6)

• Record mono sound (need microphone)

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Praat (4/6)

• Record• Stop• Save to list

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Praat (5/6)

• View & Edit

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Praat (6/6)

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Wavesurfer (1/4)

• File/Open

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Wavesurfer (2/4)

• Choose “Speech analysis”– Do NOT check “default” (next time will crash)

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Wavesurfer (3/4)

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Wavesurfer (4/4)

• Right click and create other panes you need– Ex: power plot

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Summer Assignment

• Use praat or wavesurfer to analyze a .wav file

• Can you identify any phone by spectrogram?• What kind of vowels or consonants are there?• Can you recognize pitch and formants?

• Try out more functions of these tools!

Thank You

Questions?

r01942043@ntu.edu.tw