Embedded Speech & Text-to-Speech

DECtalk, FonixTalk, Voice-In & Embedded TTS

Guides to legacy and embedded speech technologies

Read DECtalk guide

Historical overview & technical reference

What DECtalk, FonixTalk, and Voice-In were built for

This site is an independent reference about embedded voice recognition and text-to-speech — including DECtalk, FonixTalk, and Voice-In, technologies historically associated with SpeechFX, Inc. (formerly Fonix Speech) in Lindon, Utah.

The guides explain how these engines worked, where they appeared in consumer electronics, automotive systems, assistive technology, and games, and how embedded speech compares to modern cloud APIs. This is not the former company and does not offer licensing or support.

Technology guides

Read guides on DECtalk, FonixTalk, Voice-In, text-to-speech architecture, and DECtalk on Linux.

Why embedded speech mattered

Embedded speech engines were built for hardware where speed, memory, and offline operation mattered — often running on low-power devices without constant cloud connectivity.

Use cases include:

  • Smartphones and tablets
  • Smart TVs and connected appliances
  • Educational software and digital dictionaries
  • Video games and interactive toys
  • GPS navigation and automotive systems
  • Assistive devices and accessibility solutions

Voice-enabled interfaces improved accessibility and hands-free control in products from GPS units and toys to assistive reading devices.

Legacy products covered here

The historical SpeechFX product line included DECtalk (text-to-speech), FonixTalk (embedded TTS), and Voice-In (speech recognition). OEMs once licensed these engines for voice control and synthesis in shipped products.

Typical commercial arrangements in this space included:

Licensing model (historical)

How OEMs historically licensed embedded speech engines.

Royalty-based licensing

Per-unit royalties were common between speech vendors and hardware partners.

Cross-platform deployment

DECtalk and related engines targeted multiple embedded platforms.

Platform integration

Platform ports and tuning were typical for embedded speech integrations.

For developers and researchers

These articles focus on technical history and architecture. For current products and licensing, contact the relevant rights holders — this site does not represent the former SpeechFX, Inc.

Guides: DECtalk · FonixTalk · Voice-In · Text-to-Speech · DECtalk on Linux

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Browse technology guides

Independent reference — not the former SpeechFX, Inc.

© 2025 SpeechFX Technology Guide. Independent reference — not affiliated with the former SpeechFX, Inc. or Fonix Corporation.