Inworld TTS-1

Inworld TTS-1 API Overview

Inworld TTS-1 is a state-of-the-art Transformer-based autoregressive text-to-speech (TTS) model designed for high-quality, real-time speech synthesis across multiple languages. It offers low latency audio generation at high resolution (48 kHz), supports fine-grained emotional control, and is optimized for both on-device and cloud applications.

Technical Specifications

• Architecture: Transformer-based autoregressive model
• Parameter count: 1.6B (TTS-1)
• Sample rate: Up to 48 kHz high-resolution audio
• Latency: Low-latency synthesis suitable for real-time applications
• Languages supported: 11 languages with multilingual capabilities
• Emotion control: Fine-grained emotional expressiveness

Performance Benchmarks

The model outperforms many competitive models in terms of multilingual speech quality, emotional control, and latency.

Key Features

• Supports high-fidelity 48 kHz speech generation with super-resolution techniques for audio clarity
• Fine-grained emotional and prosodic control allowing nuanced speech output
• Multilingual support with consistent quality across 11 languages
• Efficient architecture optimized for both cloud and edge deployments
• Large training dataset comprising over 300,000 hours of English and Chinese speech data enhancing naturalness and robustness

API Pricing

• $5.25 / 1M characters (≈ $0.00525 / minute)

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Code Sample

Comparison with Other Models

vs Google WaveNet: Inworld TTS-1 offers lower latency and better real-time synthesis capabilities, making it ideal for interactive applications, whereas WaveNet provides highly natural and expressive speech but with higher computational cost.

vs 11LABS Multilingual V2: Inworld TTS-1 provides finer emotional nuance and lower latency for live interaction use cases, whereas 11LABS offers strong multilingual capabilities with a simpler interface. 11LABS is favored for ease of use, while Inworld TTS-1 is preferred for premium, expressive output.

vs OpenAI TTS-1-HD: OpenAI TTS-1-HD produces ultra-high-definition audio with studio-quality fidelity, surpassing Inworld in audio richness but at the expense of higher latency and cost. Inworld TTS-1 is more cost-efficient and versatile for multilingual and device-flexible deployments, making it suited for everyday real-time needs.