Added in API level 11

Summary: Constants | Inherited Constants | Methods | Inherited Methods

BluetoothHeadset

Kotlin |Java

public final class BluetoothHeadset
extends Object implements BluetoothProfile

java.lang.Object
↳	android.bluetooth.BluetoothHeadset

Public API for controlling the Bluetooth Headset Service. This includes both Bluetooth Headset and Handsfree (v1.5) profiles.

BluetoothHeadset is a proxy object for controlling the Bluetooth Headset Service via IPC.

Use BluetoothAdapter.getProfileProxy to get the BluetoothHeadset proxy object. Use BluetoothAdapter.closeProfileProxy to close the service connection.

Android only supports one connected Bluetooth Headset at a time. Each method is protected with its appropriate permission.

Summary

Constants
`String`	`ACTION_AUDIO_STATE_CHANGED` Intent used to broadcast the change in the Audio Connection state of the HFP profile.
`String`	`ACTION_CONNECTION_STATE_CHANGED` Intent used to broadcast the change in connection state of the Headset profile.
`String`	`ACTION_VENDOR_SPECIFIC_HEADSET_EVENT` Intent used to broadcast that the headset has posted a vendor-specific event.
`int`	`AT_CMD_TYPE_ACTION` AT command type ACTION used with `EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE` For example, AT+CHUP.
`int`	`AT_CMD_TYPE_BASIC` AT command type BASIC used with `EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE` For example, ATD.
`int`	`AT_CMD_TYPE_READ` AT command type READ used with `EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE` For example, AT+VGM?.
`int`	`AT_CMD_TYPE_SET` AT command type SET used with `EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE` For example, AT+VGM=.
`int`	`AT_CMD_TYPE_TEST` AT command type TEST used with `EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE` For example, AT+VGM=?.
`String`	`EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_ARGS` A Parcelable String array extra field in `ACTION_VENDOR_SPECIFIC_HEADSET_EVENT` intents that contains the arguments to the vendor-specific command.
`String`	`EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD` A String extra field in `ACTION_VENDOR_SPECIFIC_HEADSET_EVENT` intents that contains the name of the vendor-specific command.
`String`	`EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE` An int extra field in `ACTION_VENDOR_SPECIFIC_HEADSET_EVENT` intents that contains the AT command type of the vendor-specific command.
`int`	`STATE_AUDIO_CONNECTED` Headset state when SCO audio is connected.
`int`	`STATE_AUDIO_CONNECTING` Headset state when SCO audio is connecting.
`int`	`STATE_AUDIO_DISCONNECTED` Headset state when SCO audio is not connected.
`String`	`VENDOR_RESULT_CODE_COMMAND_ANDROID` A vendor-specific command for unsolicited result code.
`String`	`VENDOR_SPECIFIC_HEADSET_EVENT_COMPANY_ID_CATEGORY` The intent category to be used with `ACTION_VENDOR_SPECIFIC_HEADSET_EVENT` for the companyId

Inherited constants

From interface android.bluetooth.BluetoothProfile

`int`	`A2DP` A2DP profile.
`int`	`CSIP_SET_COORDINATOR` Coordinated Set Identification Profile set coordinator
`String`	`EXTRA_PREVIOUS_STATE` Extra for the connection state intents of the individual profiles.
`String`	`EXTRA_STATE` Extra for the connection state intents of the individual profiles.
`int`	`GATT` GATT
`int`	`GATT_SERVER` GATT_SERVER
`int`	`HAP_CLIENT`
`int`	`HEADSET` Headset and Handsfree profile
`int`	`HEALTH` This constant was deprecated in API level 29. Health Device Profile (HDP) and MCAP protocol are no longer used. New apps should use Bluetooth Low Energy based solutions such as `BluetoothGatt`, `BluetoothAdapter.listenUsingL2capChannel()`, or `BluetoothDevice.createL2capChannel(int)`
`int`	`HEARING_AID` Hearing Aid Device
`int`	`HID_DEVICE` HID Device
`int`	`LE_AUDIO` LE Audio Device
`int`	`SAP` SAP Profile
`int`	`STATE_CONNECTED` The profile is in connected state
`int`	`STATE_CONNECTING` The profile is in connecting state
`int`	`STATE_DISCONNECTED` The profile is in disconnected state
`int`	`STATE_DISCONNECTING` The profile is in disconnecting state

Public methods
`List<BluetoothDevice>`	`getConnectedDevices()` Get connected devices for this specific profile. For apps targeting `Build.VERSION_CODES.S` or or higher, this requires the `Manifest.permission.BLUETOOTH_CONNECT` permission which can be gained with `Activity.requestPermissions(String[], int)`.
`int`	`getConnectionState(BluetoothDevice device)` Get the current connection state of the profile For apps targeting `Build.VERSION_CODES.S` or or higher, this requires the `Manifest.permission.BLUETOOTH_CONNECT` permission which can be gained with `Activity.requestPermissions(String[], int)`.
`List<BluetoothDevice>`	`getDevicesMatchingConnectionStates(int[] states)` Get a list of devices that match any of the given connection states. For apps targeting `Build.VERSION_CODES.S` or or higher, this requires the `Manifest.permission.BLUETOOTH_CONNECT` permission which can be gained with `Activity.requestPermissions(String[], int)`.
`boolean`	`isAudioConnected(BluetoothDevice device)` Check if Bluetooth SCO audio is connected.
`boolean`	`isNoiseReductionSupported(BluetoothDevice device)` Checks whether the headset supports some form of noise reduction For apps targeting `Build.VERSION_CODES.R` or lower, this requires the `Manifest.permission.BLUETOOTH` permission which can be gained with a simple `<uses-permission>` manifest tag.
`boolean`	`isVoiceRecognitionSupported(BluetoothDevice device)` Checks whether the headset supports voice recognition For apps targeting `Build.VERSION_CODES.R` or lower, this requires the `Manifest.permission.BLUETOOTH` permission which can be gained with a simple `<uses-permission>` manifest tag.
`boolean`	`sendVendorSpecificResultCode(BluetoothDevice device, String command, String arg)` Sends a vendor-specific unsolicited result code to the headset.
`boolean`	`startVoiceRecognition(BluetoothDevice device)` Start Bluetooth voice recognition.
`boolean`	`stopVoiceRecognition(BluetoothDevice device)` Stop Bluetooth Voice Recognition mode, and shut down the Bluetooth audio path.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface


        
          android.bluetooth.BluetoothProfile

`abstract List<BluetoothDevice>`	`getConnectedDevices()` Get connected devices for this specific profile.
`abstract int`	`getConnectionState(BluetoothDevice device)` Get the current connection state of the profile
`abstract List<BluetoothDevice>`	`getDevicesMatchingConnectionStates(int[] states)` Get a list of devices that match any of the given connection states.

Constants

ACTION_AUDIO_STATE_CHANGED

Added in API level 11

public static final String ACTION_AUDIO_STATE_CHANGED

Intent used to broadcast the change in the Audio Connection state of the HFP profile.

This intent will have 3 extras:

BluetoothProfile.EXTRA_STATE - The current state of the profile.
BluetoothProfile.EXTRA_PREVIOUS_STATE- The previous state of the profile.
BluetoothDevice.EXTRA_DEVICE - The remote device.

BluetoothProfile.EXTRA_STATE or BluetoothProfile.EXTRA_PREVIOUS_STATE can be any of STATE_AUDIO_CONNECTED, STATE_AUDIO_DISCONNECTED,
For apps targeting Build.VERSION_CODES.R or lower, this requires the Manifest.permission.BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES.S or or higher, this requires the Manifest.permission.BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Constant Value: "android.bluetooth.headset.profile.action.AUDIO_STATE_CHANGED"

ACTION_CONNECTION_STATE_CHANGED

Added in API level 11

public static final String ACTION_CONNECTION_STATE_CHANGED

Intent used to broadcast the change in connection state of the Headset profile.

This intent will have 3 extras:

BluetoothProfile.EXTRA_STATE - The current state of the profile.
BluetoothProfile.EXTRA_PREVIOUS_STATE- The previous state of the profile.
BluetoothDevice.EXTRA_DEVICE - The remote device.

BluetoothProfile.EXTRA_STATE or BluetoothProfile.EXTRA_PREVIOUS_STATE can be any of BluetoothProfile.STATE_DISCONNECTED, BluetoothProfile.STATE_CONNECTING, BluetoothProfile.STATE_CONNECTED, BluetoothProfile.STATE_DISCONNECTING.
For apps targeting Build.VERSION_CODES.R or lower, this requires the Manifest.permission.BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES.S or or higher, this requires the Manifest.permission.BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Constant Value: "android.bluetooth.headset.profile.action.CONNECTION_STATE_CHANGED"

ACTION_VENDOR_SPECIFIC_HEADSET_EVENT

Added in API level 11

public static final String ACTION_VENDOR_SPECIFIC_HEADSET_EVENT

Intent used to broadcast that the headset has posted a vendor-specific event.

This intent will have 4 extras and 1 category.

BluetoothDevice.EXTRA_DEVICE - The remote Bluetooth Device
EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD - The vendor specific command
EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE - The AT command type which can be one of AT_CMD_TYPE_READ, AT_CMD_TYPE_TEST, or AT_CMD_TYPE_SET, AT_CMD_TYPE_BASIC,AT_CMD_TYPE_ACTION.
EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_ARGS - Command arguments.

The category is the Company ID of the vendor defining the vendor-specific command. BluetoothAssignedNumbers

For example, for Plantronics specific events Category will be VENDOR_SPECIFIC_HEADSET_EVENT_COMPANY_ID_CATEGORY.55

For example, an AT+XEVENT=foo,3 will get translated into

EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD = +XEVENT
EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE = AT_CMD_TYPE_SET
EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_ARGS = foo, 3

For apps targeting Build.VERSION_CODES.R or lower, this requires the Manifest.permission.BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES.S or or higher, this requires the Manifest.permission.BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Constant Value: "android.bluetooth.headset.action.VENDOR_SPECIFIC_HEADSET_EVENT"

AT_CMD_TYPE_ACTION

Added in API level 11

public static final int AT_CMD_TYPE_ACTION

AT command type ACTION used with EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE For example, AT+CHUP. There are no arguments for action commands.

Constant Value: 4 (0x00000004)

AT_CMD_TYPE_BASIC

Added in API level 11

public static final int AT_CMD_TYPE_BASIC

AT command type BASIC used with EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE For example, ATD. Single character commands and everything following the character are arguments.

Constant Value: 3 (0x00000003)

AT_CMD_TYPE_READ

Added in API level 11

public static final int AT_CMD_TYPE_READ

AT command type READ used with EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE For example, AT+VGM?. There are no arguments for this command type.

Constant Value: 0 (0x00000000)

AT_CMD_TYPE_SET

Added in API level 11

public static final int AT_CMD_TYPE_SET

AT command type SET used with EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE For example, AT+VGM=.

Constant Value: 2 (0x00000002)

AT_CMD_TYPE_TEST

Added in API level 11

public static final int AT_CMD_TYPE_TEST

AT command type TEST used with EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE For example, AT+VGM=?. There are no arguments for this command type.

Constant Value: 1 (0x00000001)

EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_ARGS

Added in API level 11

public static final String EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_ARGS

A Parcelable String array extra field in ACTION_VENDOR_SPECIFIC_HEADSET_EVENT intents that contains the arguments to the vendor-specific command.

Constant Value: "android.bluetooth.headset.extra.VENDOR_SPECIFIC_HEADSET_EVENT_ARGS"

EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD

Added in API level 11

public static final String EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD

A String extra field in ACTION_VENDOR_SPECIFIC_HEADSET_EVENT intents that contains the name of the vendor-specific command.

Constant Value: "android.bluetooth.headset.extra.VENDOR_SPECIFIC_HEADSET_EVENT_CMD"

EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE

Added in API level 11

public static final String EXTRA_VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE

An int extra field in ACTION_VENDOR_SPECIFIC_HEADSET_EVENT intents that contains the AT command type of the vendor-specific command.

Constant Value: "android.bluetooth.headset.extra.VENDOR_SPECIFIC_HEADSET_EVENT_CMD_TYPE"

STATE_AUDIO_CONNECTED

Added in API level 11

public static final int STATE_AUDIO_CONNECTED

Headset state when SCO audio is connected. This state can be one of BluetoothProfile.EXTRA_STATE or BluetoothProfile.EXTRA_PREVIOUS_STATE of ACTION_AUDIO_STATE_CHANGED intent.

Constant Value: 12 (0x0000000c)

STATE_AUDIO_CONNECTING

Added in API level 11

public static final int STATE_AUDIO_CONNECTING

Headset state when SCO audio is connecting. This state can be one of BluetoothProfile.EXTRA_STATE or BluetoothProfile.EXTRA_PREVIOUS_STATE of ACTION_AUDIO_STATE_CHANGED intent.

Constant Value: 11 (0x0000000b)

STATE_AUDIO_DISCONNECTED

Added in API level 11

public static final int STATE_AUDIO_DISCONNECTED

Headset state when SCO audio is not connected. This state can be one of BluetoothProfile.EXTRA_STATE or BluetoothProfile.EXTRA_PREVIOUS_STATE of ACTION_AUDIO_STATE_CHANGED intent.

Constant Value: 10 (0x0000000a)

VENDOR_RESULT_CODE_COMMAND_ANDROID

Added in API level 19

public static final String VENDOR_RESULT_CODE_COMMAND_ANDROID

A vendor-specific command for unsolicited result code.

Constant Value: "+ANDROID"

VENDOR_SPECIFIC_HEADSET_EVENT_COMPANY_ID_CATEGORY

Added in API level 11

public static final String VENDOR_SPECIFIC_HEADSET_EVENT_COMPANY_ID_CATEGORY

The intent category to be used with ACTION_VENDOR_SPECIFIC_HEADSET_EVENT for the companyId

Constant Value: "android.bluetooth.headset.intent.category.companyid"

Public methods

getConnectedDevices

Added in API level 11

public List<BluetoothDevice> getConnectedDevices ()

Get connected devices for this specific profile.

Return the set of devices which are in state STATE_CONNECTED
For apps targeting Build.VERSION_CODES.S or or higher, this requires the Manifest.permission.BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Returns
`List<BluetoothDevice>`	List of devices. The list will be empty on error.

getConnectionState

Added in API level 11

public int getConnectionState (BluetoothDevice device)

Get the current connection state of the profile
For apps targeting Build.VERSION_CODES.S or or higher, this requires the Manifest.permission.BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`device`	`BluetoothDevice`: Remote bluetooth device.

Returns
`int`	State of the profile connection. One of `STATE_CONNECTED`, `STATE_CONNECTING`, `STATE_DISCONNECTED`, `STATE_DISCONNECTING` Value is `STATE_DISCONNECTED`, `STATE_CONNECTING`, `STATE_CONNECTED`, or `STATE_DISCONNECTING`

getDevicesMatchingConnectionStates

Added in API level 11

public List<BluetoothDevice> getDevicesMatchingConnectionStates (int[] states)

Get a list of devices that match any of the given connection states.

If none of the devices match any of the given states, an empty list will be returned.
For apps targeting Build.VERSION_CODES.S or or higher, this requires the Manifest.permission.BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`states`	`int`: Array of states. States can be one of `BluetoothProfile.STATE_CONNECTED`, `BluetoothProfile.STATE_CONNECTING`, `BluetoothProfile.STATE_DISCONNECTED`, `BluetoothProfile.STATE_DISCONNECTING`,

Returns
`List<BluetoothDevice>`	List of devices. The list will be empty on error.

isAudioConnected

Added in API level 11

public boolean isAudioConnected (BluetoothDevice device)

Check if Bluetooth SCO audio is connected.
For apps targeting Build.VERSION_CODES.R or lower, this requires the Manifest.permission.BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES.S or or higher, this requires the Manifest.permission.BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`device`	`BluetoothDevice`: Bluetooth headset

Returns
`boolean`	true if SCO is connected, false otherwise or on error

isNoiseReductionSupported

Added in API level 31

public boolean isNoiseReductionSupported (BluetoothDevice device)

Checks whether the headset supports some form of noise reduction
For apps targeting Build.VERSION_CODES.R or lower, this requires the Manifest.permission.BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES.S or or higher, this requires the Manifest.permission.BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`device`	`BluetoothDevice`: Bluetooth device This value cannot be `null`.

Returns
`boolean`	true if echo cancellation and/or noise reduction is supported, false otherwise

isVoiceRecognitionSupported

Added in API level 31

public boolean isVoiceRecognitionSupported (BluetoothDevice device)

Checks whether the headset supports voice recognition
For apps targeting Build.VERSION_CODES.R or lower, this requires the Manifest.permission.BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES.S or or higher, this requires the Manifest.permission.BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`device`	`BluetoothDevice`: Bluetooth device This value cannot be `null`.

Returns
`boolean`	true if voice recognition is supported, false otherwise

sendVendorSpecificResultCode

Added in API level 19

public boolean sendVendorSpecificResultCode (BluetoothDevice device, 
                String command, 
                String arg)

Sends a vendor-specific unsolicited result code to the headset.

The actual string to be sent is command + ": " + arg. For example, if command is VENDOR_RESULT_CODE_COMMAND_ANDROID and arg is "0", the string "+ANDROID: 0" will be sent.

Currently only VENDOR_RESULT_CODE_COMMAND_ANDROID is allowed as command.
For apps targeting Build.VERSION_CODES.R or lower, this requires the Manifest.permission.BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES.S or or higher, this requires the Manifest.permission.BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`device`	`BluetoothDevice`: Bluetooth headset.
`command`	`String`: A vendor-specific command.
`arg`	`String`: The argument that will be attached to the command.

Returns
`boolean`	`false` if there is no headset connected, or if the command is not an allowed vendor-specific unsolicited result code, or on error. `true` otherwise.

Throws
`IllegalArgumentException`	if `command` is `null`.

startVoiceRecognition

Added in API level 11

public boolean startVoiceRecognition (BluetoothDevice device)

Start Bluetooth voice recognition. This methods sends the voice recognition AT command to the headset and establishes the audio connection.

Users can listen to ACTION_AUDIO_STATE_CHANGED. If this function returns true, this intent will be broadcasted with BluetoothProfile.EXTRA_STATE set to STATE_AUDIO_CONNECTING.

BluetoothProfile.EXTRA_STATE will transition from STATE_AUDIO_CONNECTING to STATE_AUDIO_CONNECTED when audio connection is established and to STATE_AUDIO_DISCONNECTED in case of failure to establish the audio connection.
For apps targeting Build.VERSION_CODES.R or lower, this requires the Manifest.permission.BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES.S or or higher, this requires the Manifest.permission.BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`device`	`BluetoothDevice`: Bluetooth headset

Returns
`boolean`	false if there is no headset connected, or the connected headset doesn't support voice recognition, or voice recognition is already started, or audio channel is occupied, or on error, true otherwise

stopVoiceRecognition

Added in API level 11

public boolean stopVoiceRecognition (BluetoothDevice device)

Stop Bluetooth Voice Recognition mode, and shut down the Bluetooth audio path.

Users can listen to ACTION_AUDIO_STATE_CHANGED. If this function returns true, this intent will be broadcasted with BluetoothProfile.EXTRA_STATE set to STATE_AUDIO_DISCONNECTED.
For apps targeting Build.VERSION_CODES.R or lower, this requires the Manifest.permission.BLUETOOTH permission which can be gained with a simple <uses-permission> manifest tag.
For apps targeting Build.VERSION_CODES.S or or higher, this requires the Manifest.permission.BLUETOOTH_CONNECT permission which can be gained with Activity.requestPermissions(String[], int).
Requires Manifest.permission.BLUETOOTH_CONNECT

Parameters
`device`	`BluetoothDevice`: Bluetooth headset

Returns
`boolean`	false if there is no headset connected, or voice recognition has not started, or voice recognition has ended on this headset, or on error, true otherwise