# OTAudioFormat Class Reference

Inherits from | NSObject
Declared in | OTAudioKit.h

## Overview

Defines the format of the audio when a custom audio driver is used.

Note that on iOS devices, specify a sample rate of 32, 16, or 8 kHz (32000, 16000, or 8000); do not use a sample rate of 44.1 kHz on iOS devices. On the simulator, however, the sampling rate must be 44.1 kHz (44100) in order to properly capture and render audio.

Currently, the only available sample format is signed 16-bit integer PCM.

### `sampleRate`

The sample rate (in samples per second). For example, set this to 32000 for 32 kHz. The default value is 16000 (16kHz).

`@property (nonatomic, assign) uint16_t sampleRate`

#### Declared In

`OTAudioKit.h`

### `numChannels`

The number of audio channels. Currently, we support only 1 channel (mono) in iOS, and this is the default.

`@property (nonatomic, assign) uint8_t numChannels`

#### Declared In

`OTAudioKit.h`