Glossary · AI & Data

Text-to-Speech (TTS)

Text-to-speech converts written text into spoken audio using synthesis models, used for assistants, accessibility, navigation and narration.

Updated October 6, 2026

Text-to-speech (TTS) is technology that turns written text into synthetic spoken audio. Older systems stitched together recorded sound fragments; current neural TTS generates a spectrogram or waveform directly from text, producing far more natural rhythm, stress and intonation.

Why it matters

TTS makes content accessible to people with visual impairments or reading difficulties, powers voice assistants and navigation prompts, and lets teams narrate articles or training material without recording sessions. Quality varies in pronunciation of names, abbreviations, numbers and mixed languages. Voice cloning raises consent and fraud concerns, and many jurisdictions and platforms require disclosure or permission when imitating a real person's voice.

Example

Input text:  "Your site example.com was down for 4 minutes at 02:10."
Markup hint: <say-as> for the time, pronunciation override for the domain
Output:      audio file (e.g. MP3) read by a chosen voice

Many engines accept SSML, a markup language for pauses, emphasis and pronunciation.

Common mistakes

  • Not expanding abbreviations or formatting numbers, producing awkward speech.
  • Cloning a voice without the speaker's permission.
  • Generating audio on every request instead of caching repeated phrases.

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