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
Outline
• Acoustics (聲學)
• Phonetics (語音學)
• Useful Tools
2
Part 1
Acoustics
3
Acoustics (1/4)
• Oscillogram
(波形圖)
• Spectrogram
(頻譜圖)
4
Acoustics (2/4)
• Frequency
– hertz (Hz)
1
𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦 =
𝑝𝑒𝑟𝑖𝑜𝑑
• Amplitude
period
amplitude
– decibel (dB)
• Phase
phase
– degree (∘)
5
Acoustics (3/4)
• F0 (fundamental frequency 基頻)
– property of vocal fold (聲帶)vibration
– pitch (音高)
fundamental period
6
Acoustics (4/4)
• F1, F2, F3… (formant frequencies 共振頻率)
– properties of vocal tract (聲道)
– phone (音素)
F3
F2
F1
7
Part 2
Phonetics
8
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
9
Phonetics (2/4)
• Vowels
– Monophthong (單母音)
– Diphthong (雙母音)
10
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)
11
Phonetics (4/4)
• IPA consonants for English
12
Part 3
Useful Tools
13
Useful Tools
• Praat
– http://www.fon.hum.uva.nl/praat/
• Wavesurfer
– http://www.speech.kth.se/wavesurfer/index.html
14
Praat (1/6)
15
Praat (2/6)
• Read from file (.wav)
16
Praat (3/6)
• Record mono sound (need microphone)
17
Praat (4/6)
• Record
• Stop
• Save to list
18
Praat (5/6)
• View & Edit
19
Praat (6/6)
20
Wavesurfer (1/4)
• File/Open
21
Wavesurfer (2/4)
• Choose “Speech analysis”
– Do NOT check “default” (next time will crash)
22
Wavesurfer (3/4)
23
Wavesurfer (4/4)
• Right click and create other panes you need
– Ex: power plot
24
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!
25
Thank You
Questions?
r01942043@ntu.edu.tw