> ## 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.

# Deprecated Models

> Guide to migrating away from deprecated models.

As the ai-coustics SDK evolves, we occasionally deprecate older models in favor of newer, more efficient and performant ones.
This guide provides an overview of the deprecated models and recommendations for migrating to the latest versions.

<div id="quail" />

## Quail

**SDK, Real-time, Human-to-Machine**

With the release of the Quail Voice Focus 2.0 model, the older 1.0 and 1.1 VF models have been deprecated.
We recommend migrating to the Quail VF 2.0 model for improved ASR performance and VAD capabilities.

<AccordionGroup>
  <Accordion title="Quail Voice Focus 1.1 L (16 kHz)">
    * **ID:** `quail-vf-1.1-l-16khz`
    * **Last supported core SDK version:** 0.14
    * **File size:** 35 MB
    * **Window length:** 10 ms
    * **Optimal sample rate:** 16 kHz
    * **Optimal num frames:** 160
    * **Minimal algorithmic delay:** 30 ms
  </Accordion>

  <Accordion title="Quail Voice Focus 1.0 L (16 kHz)">
    * **ID:** `quail-vf-l-16khz`
    * **Last supported core SDK version:** 0.14
    * **File size:** 35 MB
    * **Window length:** 10 ms
    * **Optimal sample rate:** 16 kHz
    * **Optimal num frames:** 160
    * **Minimal algorithmic delay:** 30 ms
  </Accordion>
</AccordionGroup>

<div id="sparrow" />

## Sparrow

**SDK, Real-time, Human-to-Human**

Starting with core SDK 0.15, the smaller, ultra-low-latency Sparrow models have been deprecated.
There are currently no plans to develop alternatives to these models.

Sparrow model variants S and L continue to be supported and are recommended for real-time speech enhancement in human-to-human communication scenarios.

If you have a need for ultra-low-latency speech enhancement models, please [reach out to us](https://ai-coustics.com/contact) to discuss your use case and requirements.

<AccordionGroup>
  <Accordion title="Sparrow XS (48 kHz)">
    * **ID:** `sparrow-xs-48khz`
    * **Last supported core SDK version:** 0.14
    * **File size:** 1.62 MB
    * **Window length:** 10 ms
    * **Native sample rate:** 48 kHz
    * **Native num frames:** 480
    * **Minimal algorithmic delay:** 10 ms
  </Accordion>

  <Accordion title="Sparrow XXS (48 kHz)">
    * **ID:** `sparrow-xxs-48khz`
    * **Last supported core SDK version:** 0.14
    * **File size:** 1 MB
    * **Window length:** 10 ms
    * **Native sample rate:** 48 kHz
    * **Native num frames:** 480
    * **Minimal algorithmic delay:** 10 ms
  </Accordion>
</AccordionGroup>

## Need help?

* Check out the [models overview](/reference/sdk/models).
* Download available models at [artifacts.ai-coustics.io](https://artifacts.ai-coustics.io).