中科大语音信号处理课件ch3.pdfVIP

Chapter 3 Acoustic Theory of Speech Production 语音产生的声学理论 1 Outline • Speech production mechanism • Speech signal: waveforms and spectra • Sounds of language = phonemes(音素) • English speech sounds • Initials(声母) and finals(韵母) of Mandarin( 中文普通话) 2 Basic Speech Processes • idea→sentences →words →sounds →waveform – Idea: it’s getting late, I should go to lunch, I should call Al and see if he wants to join me for lunch today – Sentences/Words: Hi Al, did you eat yet? – Sounds: /h/ /ay/-/ae/ /l/-/d/ /ih/ /d/-/y/ /u/-/iy/ /t/-/y/ /ε/ /t/ – Coarticulated Sounds: /h- ay-l/-/d-ih-j-uh/-/iy-t-j-ε-t/ (hial- dija-eajet) 3 Basic Speech Processes • remarkably, humans can decode these sounds and determine the meaning that was intended—at least at the idea/concept level (perhaps not completely at the word or sound level) • often machines can also do the same task – speech coding: waveform →(model) →waveform – speech synthesis: words →waveform – speech recognition: waveform →words/sentences – speech understanding: waveform →idea 4 Basics • speech is composed of a sequence of sounds • sounds (and transitions between them) serve as a symbolic representation of information to be shared between humans (or humans and machines) • arrangement of sounds is governed by rules of language (constraints on sound sequences, word sequences, etc)-- /spl/ exists, /sbk/ doesn’t exist • linguistics(语言学) is the study of the rule