---
title: Audio Session Support
framework: audiotoolbox
role: collectionGroup
role_heading: API Collection
path: audiotoolbox/audio-session-support
---

# Audio Session Support

Describe the properties that you associate with audio sessions and audio routes.

## Overview

Overview important: The AudioSession API has been completely deprecated in iOS 7.0. See AVAudioSession for the Objective-C implementation of these functions. Audio Session Services lets you specify the intended audio behavior for your iOS app. For example, you can specify whether you intend for your app’s audio to silence other apps or to mix with their audio. You also use this API to specify your app’s behavior when it is interrupted, such as by a phone call. When the system knows your intentions, it configures the audio hardware in the device to satisfy those intentions, as possible. These functions apply only to iOS. They do not apply to macOS.

## Topics

### Audio Session Support

- [Audio Session Property Identifiers](audiotoolbox/1618455-audio-session-property-identifie.md)
- [Audio Session Categories](audiotoolbox/1618427-audio-session-categories.md)
- [Audio Session Modes](audiotoolbox/1618405-audio-session-modes.md)
- [Audio Session Category Route Overrides](audiotoolbox/1618372-audio-session-category-route-ove.md)
- [Audio Session Activation Flags](audiotoolbox/1618357-audio-session-activation-flags.md)
- [Audio Session Interruption States](audiotoolbox/1618425-audio-session-interruption-state.md)
- [AudioSessionInterruptionType](audiotoolbox/audiosessioninterruptiontype.md)

### Audio Routes

- [Audio Route Change Reasons](audiotoolbox/1618380-audio-route-change-reasons.md)
- [Audio Route Description Dictionary Keys](audiotoolbox/audio-route-description-dictionary-keys.md)
- [Audio Route Type Key](audiotoolbox/audio-route-type-key.md)
- [Audio Input Routes](audiotoolbox/audio-input-routes.md)
- [Audio Output Routes](audiotoolbox/audio-output-routes.md)
- [Audio Route Change Dictionary Keys](audiotoolbox/audio-route-change-dictionary-keys.md)
- [Alternative Audio Route Change Reason Dictionary Key](audiotoolbox/alternative-audio-route-change-reason-dictionary-key.md)

### USB Accessories

- [USB Accessory Audio Source Dictionary Keys](audiotoolbox/usb-accessory-audio-source-dictionary-keys.md)
- [USB Accessory Audio Destination Dictionary Keys](audiotoolbox/usb-accessory-audio-destination-dictionary-keys.md)

### Constants

- [kAudioSessionInputRoute_BluetoothHFP](audiotoolbox/kaudiosessioninputroute_bluetoothhfp.md)
- [kAudioSessionInputRoute_BuiltInMic](audiotoolbox/kaudiosessioninputroute_builtinmic.md)
- [kAudioSessionInputRoute_HeadsetMic](audiotoolbox/kaudiosessioninputroute_headsetmic.md)
- [kAudioSessionInputRoute_LineIn](audiotoolbox/kaudiosessioninputroute_linein.md)
- [kAudioSessionInputRoute_USBAudio](audiotoolbox/kaudiosessioninputroute_usbaudio.md)
- [kAudioSessionOutputRoute_AirPlay](audiotoolbox/kaudiosessionoutputroute_airplay.md)
- [kAudioSessionOutputRoute_BluetoothA2DP](audiotoolbox/kaudiosessionoutputroute_bluetootha2dp.md)
- [kAudioSessionOutputRoute_BluetoothHFP](audiotoolbox/kaudiosessionoutputroute_bluetoothhfp.md)
- [kAudioSessionOutputRoute_BuiltInReceiver](audiotoolbox/kaudiosessionoutputroute_builtinreceiver.md)
- [kAudioSessionOutputRoute_BuiltInSpeaker](audiotoolbox/kaudiosessionoutputroute_builtinspeaker.md)
- [kAudioSessionOutputRoute_HDMI](audiotoolbox/kaudiosessionoutputroute_hdmi.md)
- [kAudioSessionOutputRoute_Headphones](audiotoolbox/kaudiosessionoutputroute_headphones.md)
- [kAudioSessionOutputRoute_LineOut](audiotoolbox/kaudiosessionoutputroute_lineout.md)
- [kAudioSessionOutputRoute_USBAudio](audiotoolbox/kaudiosessionoutputroute_usbaudio.md)
- [kAudioSession_AudioRouteChangeKey_CurrentRouteDescription](audiotoolbox/kaudiosession_audioroutechangekey_currentroutedescription.md)
- [kAudioSession_AudioRouteChangeKey_PreviousRouteDescription](audiotoolbox/kaudiosession_audioroutechangekey_previousroutedescription.md)
- [kAudioSession_AudioRouteKey_Inputs](audiotoolbox/kaudiosession_audioroutekey_inputs.md)
- [kAudioSession_AudioRouteKey_Outputs](audiotoolbox/kaudiosession_audioroutekey_outputs.md)
- [kAudioSession_AudioRouteKey_Type](audiotoolbox/kaudiosession_audioroutekey_type.md)
- [kAudioSession_InputSourceKey_Description](audiotoolbox/kaudiosession_inputsourcekey_description.md)
- [kAudioSession_InputSourceKey_ID](audiotoolbox/kaudiosession_inputsourcekey_id.md)
- [kAudioSession_OutputDestinationKey_Description](audiotoolbox/kaudiosession_outputdestinationkey_description.md)
- [kAudioSession_OutputDestinationKey_ID](audiotoolbox/kaudiosession_outputdestinationkey_id.md)
- [kAudioSession_RouteChangeKey_Reason](audiotoolbox/kaudiosession_routechangekey_reason.md)

### Enumerations

- [Audio Session Interruption Types](audiotoolbox/1618387-audio-session-interruption-types.md)

### Result Codes

- [Audio Session Errors](audiotoolbox/1618373-audio-session-errors.md)

## See Also

### Utilities

- [Analyzing audio performance with Instruments](audiotoolbox/analyzing-audio-performance-with-instruments.md)
- [Audio Converter Services](audiotoolbox/audio-converter-services.md)
- [Audio Toolbox Debugging](audiotoolbox/audio-toolbox-debugging.md)
- [Workgroup Management](audiotoolbox/workgroup-management.md)
- [Audio Codec](audiotoolbox/audio-codec.md)
- [Clock Utilities](audiotoolbox/clock-utilities.md)