Voice AI

What is Voice AI?

Voice AI includes technologies that enable computers to understand human speech and generate spoken responses. It powers Siri, Alexa, Google Assistant, and increasingly natural-sounding AI voices.

Speech Recognition (Speech-to-Text)

Converting spoken words into written text. Also called ASR (Automatic Speech Recognition).

How It Works

1. Audio is captured and processed
2. Sound is converted to spectrograms (visual representations)
3. Neural networks recognize patterns as words
4. Language models predict likely word sequences

Key Players

• Whisper (OpenAI) — Open source, multilingual, highly accurate
• Google Speech-to-Text — Powers Google Assistant
• Azure Speech — Microsoft's offering

Text-to-Speech (TTS)

Converting written text into natural-sounding speech.

Evolution

• Old — Robotic, obviously synthetic
• Modern — Nearly indistinguishable from human speech

Key Players

• ElevenLabs — Realistic voice cloning
• Amazon Polly — Powers Alexa voices
• Google TTS — Natural-sounding voices

Voice Cloning

Creating synthetic copies of specific voices. With just minutes of audio, AI can generate new speech in someone's voice.

• Uses: Personalized assistants, preserving voices of loved ones, accessibility
• Risks: Fraud, impersonation, non-consensual use

Voice Assistants

Complete systems combining speech recognition, understanding, and response:

• Amazon Alexa
• Apple Siri
• Google Assistant
• Microsoft Cortana

Challenges

• Accents and dialects — Performance varies across speakers
• Background noise — Hard to isolate speech in noisy environments
• Context — Understanding intent, not just words
• Privacy — Always-listening devices raise concerns