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Natural Language Services

AWS services for natural language processing

⏱️ Estimated reading time: 20 minutes

Amazon Comprehend

Natural Language Processing (NLP) service that uses ML to extract insights from text.

Main Capabilities



Sentiment Analysis


- Determines if text is positive, negative, neutral, or mixed
- Confidence score for each sentiment
- Useful for customer opinion analysis

Entity Extraction


Identifies and categorizes entities:
- People: Individual names
- Places: Geographic locations
- Organizations: Companies, institutions
- Dates: Temporal references
- Quantities: Numbers, percentages
- Events: Occurrences

Language Detection


- Identifies the primary language of text
- Supports 100+ languages

Key Phrase Extraction


- Identifies important terms and phrases
- Useful for summaries and categorization

Syntax Analysis


- Part-of-speech tagging (verbs, nouns, etc.)
- Grammatical analysis

Topic Modeling


- Discovers topics in document collections
- Groups documents by topic

Document Classification


- Predefined: Standard categories
- Custom: Train with your own categories

PII Detection (Personally Identifiable Information)


- Finds sensitive data:
- Names
- Addresses
- Credit card numbers
- SSN, passports
- Automatic redaction option

Amazon Comprehend Medical



Specialized in medical texts:
- Extracts medical information
- Identifies conditions, medications, dosages
- Detects HIPAA-protected data
- Understands medical ontologies (ICD-10, RxNorm)

Use Cases


- Customer feedback analysis
- Automatic ticket categorization
- Social media analysis
- Intelligent document search
- Data compliance and privacy
- Medical record analysis

🎯 Key Points

  • βœ“ Comprehend is useful for quick text analysis without custom models
  • βœ“ Verify language detection and adapt tokenizers/vocabularies for specific languages
  • βœ“ Use Comprehend Medical for clinical data and regulatory compliance
  • βœ“ Measure entity extraction accuracy on real domain text
  • βœ“ Combine services (Transcribe -> Comprehend -> Translate) for multilingual pipelines

Amazon Lex and Conversational Services

Service for building conversational interfaces (chatbots) using voice and text.

Features



Automatic Speech Recognition (ASR)


- Converts speech to text
- Same technology as Alexa

Natural Language Understanding (NLU)


- Interprets user intent
- Extracts relevant information (slots)

Dialog Management


- Maintains conversation context
- Handles multiple turns
- Confirmations and clarifications

Integration


- AWS Lambda for business logic
- Amazon Connect for contact centers
- Multiple channels (web, mobile, Slack, Facebook)

Key Concepts



Intents:
- Actions the user wants to perform
- Example: BookFlight, CheckBalance

Utterances:
- Phrases users say
- Example: 'I want to book a flight'

Slots:
- Variables to extract from user
- Example: origin_city, destination_city, date

Fulfillment:
- Logic to fulfill the intent
- Typically a Lambda function

Use Cases


- Customer service chatbots
- Enterprise virtual assistants
- Contact center automation
- Booking systems
- Automated FAQs

Amazon Lex V2



Recent improvements:
- Better contextual understanding
- Support for more complex conversations
- Audio streaming
- More predictable pricing

🎯 Key Points

  • βœ“ Lex fits structured conversational flows; Bedrock/LLMs are better for open responses
  • βœ“ Integrate Lambda for secure business logic fulfillment
  • βœ“ Test with real conversations and handle long context/state
  • βœ“ Manage scalability and concurrent call costs
  • βœ“ Measure UX metrics (turns-to-resolution, fallback rate)

Speech and Translation Services

Amazon Polly



Text-to-Speech (TTS)

Features:


- High-quality neural voices
- Support for 60+ languages
- Standard and neural voices
- SSML (Speech Synthesis Markup Language)
- Pronunciation control
- Pauses, emphasis, speed
- Audio effects

Use cases:


- Reading applications
- Virtual assistants
- Accessibility
- E-learning
- IVR (phone systems)
- Content narration

Advanced Features:


- Newscaster style: News presenter style
- Brand Voice: Custom voices for companies
- Lexicons: Custom pronunciation

Amazon Transcribe



Speech-to-Text (STT)

Features:


- Automatic speech recognition
- Speaker identification
- Automatic timestamping
- Custom vocabularies
- Vocabulary filtering (forbidden words)
- Automatic PII redaction

Transcribe Medical:


- Specialized in medical terminology
- Medical consultation transcription
- HIPAA compliance

Transcribe Call Analytics:


- Contact center call analysis
- Sentiment detection
- Issue identification
- Conversation metrics

Use cases:


- Video subtitles
- Meeting transcription
- Call analysis
- Medical documentation
- Audio content search

Amazon Translate



Neural machine translation

Features:


- Real-time translation
- Support for 75+ languages
- Full document translation
- Custom terminology
- Batch translation

Active Custom Translation:


- Train models with your own data
- Domain-specific terminology
- Better quality for specialized cases

Use cases:


- Application localization
- Web content translation
- Multilingual communication
- Document translation
- International customer service

Service Integration



Complete pipeline example:
1. Transcribe: Converts audio to text
2. Comprehend: Analyzes sentiment and entities
3. Translate: Translates to other languages
4. Polly: Converts response to speech

This pipeline enables complete multilingual conversational experiences.

🎯 Key Points

  • βœ“ Polly and Transcribe enable accessible, multilingual applications
  • βœ“ Use lexicons and voice styles for brand consistency
  • βœ“ Transcribe Call Analytics provides actionable contact-center metrics
  • βœ“ Tune custom vocabularies for domain terminology
  • βœ“ Combine with Comprehend for post-transcription analysis