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

# Suppression

The `<Suppression>` noun is used inside `<Start>` and `<Stop>` verbs to control noise suppression on the call to improve audio quality.

## Attributes

<table>
  <thead>
    <tr>
      <th>ATTRIBUTE</th>
      <th>DESCRIPTION</th>
      <th>OPTIONS</th>
      <th>DEFAULT</th>
    </tr>
  </thead>

  <tbody>
    <tr>
      <td><code>direction</code></td>
      <td> Specifies which side of the audio shall be denoised. </td>
      <td><code>inbound</code>, <code>outbound</code>, <code>both</code></td>
      <td><code>inbound</code></td>
    </tr>

    <tr>
      <td><code>noiseSuppressionEngine</code></td>
      <td> The noise suppression engine to use. Defaults to `Denoiser`. </td>
      <td><code>Denoiser</code>, <code>DeepFilterNet</code>, <code>Krisp</code>, <code>AiCoustics</code></td>
      <td>-</td>
    </tr>

    <tr>
      <td><code>model</code></td>
      <td> The Krisp model to use. Only applicable when `noiseSuppressionEngine` is `Krisp`. Available models: `krisp-viva-tel-v2.kef`, `krisp-viva-tel-lite-v1.kef`, `krisp-viva-pro-v1.kef`, `krisp-viva-ss-v1.kef`. </td>

      <td />

      <td>-</td>
    </tr>

    <tr>
      <td><code>suppressionLevel</code></td>
      <td> Suppression intensity (0.0–100.0). Only applicable when `noiseSuppressionEngine` is `Krisp`. </td>

      <td />

      <td>-</td>
    </tr>
  </tbody>
</table>

## Examples

### Start suppression with default settings

```xml theme={null}
<?xml version="1.0" encoding="UTF-8"?>
<Response>
  <Start>
    <Suppression direction="both" />
  </Start>
</Response>
```

### Start suppression with Krisp engine

```xml theme={null}
<?xml version="1.0" encoding="UTF-8"?>
<Response>
  <Start>
    <Suppression
      direction="inbound"
      noiseSuppressionEngine="Krisp"
      model="krisp-viva-tel-v2.kef"
      suppressionLevel="75" />
  </Start>
</Response>
```

### Stop suppression

```xml theme={null}
<?xml version="1.0" encoding="UTF-8"?>
<Response>
  <Stop>
    <Suppression />
  </Stop>
</Response>
```