> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ai-coustics.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Quail

> Speech enhancement that improves Speech-to-Text accuracy for Voice AI.

The Quail models are purpose-built for **Voice AI Agents** and **human-to-machine** interactions. Unlike standard noise suppression, Quail is tuned to improve the performance of downstream Speech-to-Text (STT) engines.

**Quail** is a general-purpose speech enhancement model.
It works in any setting, single- or multi-speaker and near- or far-field, suppressing background noise while preserving all audible speech. This makes it a good fit whenever every voice should be kept, such as speakerphone setups, meeting rooms, or situations with multiple participants spread across a space.

For primary-speaker isolation, see [Quail Voice Focus](/models/voice-focus/quail-voice-focus).

<Warning>
  The Quail models are designed to enhance the performance of Voice AI Agents and STT systems, and may not always produce the most natural-sounding audio for human listeners.

  It is expected that some noise and reverberation may remain in the output, as these can actually help improve STT accuracy by providing additional acoustic context.

  If your primary goal is to improve the listening experience for humans, we recommend using the [Rook models](/models/perceptual-speech-enhancement/rook) instead.
</Warning>

<Note>
  Take a look at our [ASR optimization guide](/models/speech-enhancement/speech-enhancement-for-voice-ai-systems) and the [model reference](/reference/sdk/models) for available sizes and specs.
</Note>