# IOUserAudioBox A container for other audio objects, typically audio devices and audio clock devices. ``` class IOUserAudioBox; ``` ## Overview Along with containing other audio objects, [`IOUserAudioBox`](/documentation/AudioDriverKit/IOUserAudioBox) publishes identifying information about itself and allows you to enable or disable the box. When disabled, the box’s contents aren’t available. ## Topics ### Creating an Audio Box [`static OSSharedPtr Create(IOUserAudioDriver *in_driver, bool in_is_acquirable, OSString *in_box_uid);`](/documentation/AudioDriverKit/IOUserAudioBox/Create) Allocates and initializes an instance of the audio box class. [`virtual bool init(IOUserAudioDriver *in_driver, bool in_is_acquirable, OSString *in_box_uid);`](/documentation/AudioDriverKit/IOUserAudioBox/init) Initializes an instance of the audio box class. [`class IOUserAudioDriver;`](/documentation/AudioDriverKit/IOUserAudioDriver) A DriverKit provider object that manages communications with an audio device. ### Freeing an Audio Box [`virtual void free();`](/documentation/AudioDriverKit/IOUserAudioBox/free) Frees the audio box. ### Getting Information About the Class [`virtual IOUserAudioClassID GetClassID();`](/documentation/AudioDriverKit/IOUserAudioBox/GetClassID) Gets the audio class identifier of the object. [`virtual IOUserAudioClassID GetBaseClassID();`](/documentation/AudioDriverKit/IOUserAudioBox/GetBaseClassID) Gets the audio class identifier of the base class object. [`enum IOUserAudioClassID : uint32_t;`](/documentation/AudioDriverKit/AudioDriverKit/IOUserAudioClassID) An identifier for the type of audio object. ### Identifying the Box [`OSSharedPtr GetUID();`](/documentation/AudioDriverKit/IOUserAudioBox/GetUID) Returns the UID of the audio box. ### Managing Box Contents [`kern_return_t AddDevice(IOUserAudioDevice *in_device);`](/documentation/AudioDriverKit/IOUserAudioBox/AddDevice) Adds an audio device to the audio box. [`kern_return_t RemoveDevice(IOUserAudioDevice *in_device);`](/documentation/AudioDriverKit/IOUserAudioBox/RemoveDevice) Removes an audio device from the audio box. [`class IOUserAudioDevice;`](/documentation/AudioDriverKit/IOUserAudioDevice) An audio clock device object that handles the configurations for running I/O. [`kern_return_t AddClockDevice(IOUserAudioClockDevice *in_clock_device);`](/documentation/AudioDriverKit/IOUserAudioBox/AddClockDevice) Adds an audio clock device to the audio box. [`kern_return_t RemoveClockDevice(IOUserAudioClockDevice *in_clock_device);`](/documentation/AudioDriverKit/IOUserAudioBox/RemoveClockDevice) Adds an audio clock device to the audio box. [`class IOUserAudioClockDevice;`](/documentation/AudioDriverKit/IOUserAudioClockDevice) An audio clock device object, used to synchronize and perform I/O. ### Managing Protection State [`kern_return_t SetIsProtected(bool in_is_protected);`](/documentation/AudioDriverKit/IOUserAudioBox/SetIsProtected) Sets a Boolean value that indicates if the box requires authentication before use. [`bool IsProtected();`](/documentation/AudioDriverKit/IOUserAudioBox/IsProtected) Returns a Boolean value that indicates if the box requires authentication before use. ### Managing Acquirability [`virtual kern_return_t HandleChangeAcquireBox(bool in_acquire);`](/documentation/AudioDriverKit/IOUserAudioBox/HandleChangeAcquireBox) Informs the box of a change to its acquisition state. [`kern_return_t SetIsAcquired(bool in_is_acquired);`](/documentation/AudioDriverKit/IOUserAudioBox/SetIsAcquired) Set the box’s acquisition state. [`bool IsAcquired();`](/documentation/AudioDriverKit/IOUserAudioBox/IsAcquired) Returns a Boolean value that indicates the box’s acquisition state. [`kern_return_t SetIsAcquirable(bool in_is_acquirable);`](/documentation/AudioDriverKit/IOUserAudioBox/SetIsAcquirable) Set the box’s acquirability state. [`bool IsAcquirable();`](/documentation/AudioDriverKit/IOUserAudioBox/IsAcquirable) Returns a Boolean value that indicates the box’s acquirabilty state. [`kern_return_t SetAcquisitionFailure(kern_return_t in_failure_code);`](/documentation/AudioDriverKit/IOUserAudioBox/SetAcquisitionFailure) Sets the error code to return when box acquisition fails. [`kern_return_t GetAcquisitionFailure();`](/documentation/AudioDriverKit/IOUserAudioBox/GetAcquisitionFailure) Returns the error code for use when box acquisition fails. ### Determining Media Support [`kern_return_t SetHasAudio(bool in_has_audio);`](/documentation/AudioDriverKit/IOUserAudioBox/SetHasAudio) Sets a Boolean value that indicates the box’s audio support. [`bool HasAudio();`](/documentation/AudioDriverKit/IOUserAudioBox/HasAudio) Returns a Boolean value that indicates the box’s audio support. [`kern_return_t SetHasVideo(bool in_has_video);`](/documentation/AudioDriverKit/IOUserAudioBox/SetHasVideo) Sets a Boolean value that indicates the box’s video support. [`bool HasVideo();`](/documentation/AudioDriverKit/IOUserAudioBox/HasVideo) Returns a Boolean value that indicates the box’s video support. [`kern_return_t SetHasMIDI(bool in_has_midi);`](/documentation/AudioDriverKit/IOUserAudioBox/SetHasMIDI) Sets a Boolean value that indicates the box’s MIDI support. [`bool HasMIDI();`](/documentation/AudioDriverKit/IOUserAudioBox/HasMIDI) Returns a Boolean value that indicates the box’s MIDI support. ### Working with Transport Types [`kern_return_t SetTransportType(IOUserAudioTransportType in_transport_type);`](/documentation/AudioDriverKit/IOUserAudioBox/SetTransportType) Sets the box’s transport type. [`IOUserAudioTransportType GetTransportType();`](/documentation/AudioDriverKit/IOUserAudioBox/GetTransportType) Returns the box’s transport type. [`enum IOUserAudioTransportType : uint32_t;`](/documentation/AudioDriverKit/AudioDriverKit/IOUserAudioTransportType) The type of transport to deliver audio. ## Relationships ### Inherits From [`IOUserAudioObject`](/documentation/AudioDriverKit/IOUserAudioObject) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)