Phase 4 Implementation Guide - Voice Capabilities
Phase: Week 6
Status: 🚀 Starting Implementation
Goal: Add speech-to-text and text-to-speech capabilities
🎯 Phase 4 Overview
Objective: Enable voice-based interactions with the chatbot
Deliverables:
- Speech-to-text service (Whisper)
- Text-to-speech service (OpenAI TTS / Piper)
- Audio processing utilities
- Voice API endpoints
- Integration with existing UIs
Timeline: 1 week
📋 Tasks Breakdown
Day 1: Speech-to-Text
- Create STT service with Whisper
- Add local model fallback
- Implement language detection
- Add audio preprocessing
- Test transcription accuracy
Day 2: Text-to-Speech
- Create TTS service with OpenAI API
- Add Piper TTS fallback
- Implement voice selection
- Add audio post-processing
- Test speech quality
Day 3: Audio Processing
- Audio format conversion
- Noise reduction
- Audio streaming
- Chunk processing
Day 4: Voice API
- Create voice endpoints
- WebSocket streaming
- File upload/download
- Integration testing
Day 5: UI Integration & Testing
- Add voice to Gradio
- Add voice to Chainlit (optional)
- Add voice to Telegram
- End-to-end testing
🎤 Components to Build
1. Speech-to-Text Service
File: packages/voice/stt_service.py
Features:
- OpenAI Whisper API integration
- Local Whisper model fallback
- Multiple audio formats (WAV, MP3, OGG)
- Language detection
- Timestamp alignment
- Confidence scores
API:
from packages.voice import STTService
stt = STTService()
result = await stt.transcribe(audio_file="recording.mp3")
print(result.text)
2. Text-to-Speech Service
File: packages/voice/tts_service.py
Features:
- OpenAI TTS API (primary)
- Piper TTS (offline fallback)
- Multiple voices/languages
- Speed/pitch control
- Audio format options
API:
from packages.voice import TTSService
tts = TTSService()
audio_file = await tts.synthesize(
text="Hello, how can I help you?",
voice="alloy"
)
3. Audio Processing
File: packages/voice/audio_processor.py
Features:
- Format conversion
- Resampling
- Noise reduction
- Volume normalization
- Audio chunking
4. Voice API Endpoints
File: apps/api/voice_api.py
Endpoints:
POST /voice/transcribe # Upload audio, get text
POST /voice/synthesize # Send text, get audio
WS /voice/stream # Streaming audio
GET /voice/languages # Supported languages
GET /voice/voices # Available voices
🛠️ Dependencies
Install Voice Libraries
# Speech-to-Text
pip install openai-whisper>=20231117
pip install openai>=1.12.0 # For API
# Text-to-Speech
pip install piper-tts>=1.2.0
pip install TTS>=0.22.0 # Coqui TTS (alternative)
# Audio Processing
pip install pydub>=0.25.1
pip install librosa>=0.10.0
pip install soundfile>=0.12.1
# Optional: For advanced audio
pip install noisereduce>=3.0.0
pip install webrtcvad>=2.0.10
📊 Voice Providers Comparison
| Feature | OpenAI Whisper API | Local Whisper | Google STT | AWS Transcribe |
|---|---|---|---|---|
| Quality | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ |
| Speed | ⭐⭐⭐⭐ | ⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ |
| Cost | $0.006/min | 🆓 Free | $0.006/15s | $0.024/min |
| Privacy | ⚠️ Cloud | ✅ Local | ⚠️ Cloud | ⚠️ Cloud |
| Languages | 99 | 99 | 125+ | 100+ |
| Offline | ❌ | ✅ | ❌ | ❌ |
Decision: OpenAI Whisper API (primary) + Local Whisper (fallback/privacy)
| Feature | OpenAI TTS | Piper TTS | Google TTS | AWS Polly |
|---|---|---|---|---|
| Quality | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ |
| Natural | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐ |
| Speed | ⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ |
| Cost | $15/1M chars | 🆓 Free | $4/1M chars | $4/1M chars |
| Privacy | ⚠️ Cloud | ✅ Local | ⚠️ Cloud | ⚠️ Cloud |
| Voices | 6 | 50+ | 200+ | 60+ |
| Offline | ❌ | ✅ | ❌ | ❌ |
Decision: OpenAI TTS (primary) + Piper TTS (fallback/offline)
🚀 Implementation
Let's build the voice components! Starting with STT...