74.419 Artificial Intelligence 2004 Speech

1
74.419 Artificial Intelligence 2004Speech
Natural Language Processing

• Speech Recognition
• acoustic signal as input
• conversion into (phonemes and) written words
• Natural Language Processing
• written text as input sentences (or
  'utterances')
• syntactic analysis parsing grammar
• semantic analysis "meaning", semantic
  representation
• pragmatics dialogue (discourse)

2
Speech Recognition
Acoustic / sound wave
Filtering, FFT Spectral
Analysis Frequency Spectrum
Features (Phonemes Context)
Signal Processing / Analysis
Phoneme Recognition HMM, Neural
Networks Phonemes
Grammar or Statistics Phoneme Sequences /
Words
Grammar or Statistics for likely word
sequences Word Sequence / Sentence
3
NLP Syntax Analysis - Processes
Part-of-Speech (POS) Tagging
Morphological Analyzer
Parser
Grammar Rules
Lexicon
the the determiner Det NP ? Det
Noun NP recognized NP Det
Noun parse tree
Linguistic Background Knowledge
4
NLP - Syntactic Analysis
Part-of-Speech (POS) Tagging
Morphological Analyzer
Parser
Grammar Rules
Lexicon
eat s eat verb Verb VP ? Verb
Noun VP recognized 3rd sing
VP Verb Noun
parse tree