# OTCustomAudioTransformer Protocol Reference

Conforms to | NSObject
Declared in | OTPublisherKit.h

## Overview

Defines a custom transformer for an audio stream, to be passed into the [OTAudioTransformer initWithName:transformer:] method.

### `– transform:` required method

Called when audio data is available to be transformed. Transform the data in your implementation of the method.

`- (void)transform:(nonnull OTAudioData *)audioData`

#### Parameters

`audioData` | The audio data to be transformed.

#### Declared In

`OTPublisherKit.h`