# Source: https://docs.pipecat.ai/server/utilities/audio/koala-filter.md

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# KoalaFilter

> Audio noise reduction filter using Koala AI technology from Picovoice

## Overview

`KoalaFilter` is an audio processor that reduces background noise in real-time audio streams using Koala Noise Suppression technology from Picovoice. It inherits from `BaseAudioFilter` and processes audio frames to improve audio quality by removing unwanted noise.

To use Koala, you need a Picovoice access key. Get started at [Picovoice Console](https://console.picovoice.ai/signup).

## Installation

The Koala filter requires additional dependencies:

```bash  theme={null}
pip install "pipecat-ai[koala]"
```

You'll also need to set up your Koala access key as an environment variable: `KOALA_ACCESS_KEY`

## Constructor Parameters

<ParamField path="access_key" type="str" required>
  Picovoice access key for using the Koala noise suppression service
</ParamField>

## Input Frames

<ParamField path="FilterEnableFrame" type="Frame">
  Specific control frame to toggle filtering on/off

  ```python  theme={null}
  from pipecat.frames.frames import FilterEnableFrame

  # Disable noise reduction
  await task.queue_frame(FilterEnableFrame(False))

  # Re-enable noise reduction
  await task.queue_frame(FilterEnableFrame(True))
  ```
</ParamField>

## Usage Example

```python  theme={null}
from pipecat.audio.filters.koala_filter import KoalaFilter

transport = DailyTransport(
    room_url,
    token,
    "Respond bot",
    DailyParams(
        audio_in_filter=KoalaFilter(access_key=os.getenv("KOALA_ACCESS_KEY")), # Enable Koala noise reduction
        audio_in_enabled=True,
        audio_out_enabled=True,
    ),
)
```

## Notes

* Requires Picovoice access key
* Supports real-time audio processing
* Handles 16-bit PCM audio format
* Can be dynamically enabled/disabled
* Maintains audio quality while reducing noise
* Efficient processing for low latency
* Automatically handles audio frame buffering
* Sample rate must match Koala's required sample rate