---
title: "AudioDeviceStart(_:_:)"
framework: coreaudio
role: symbol
role_heading: Function
path: "coreaudio/audiodevicestart(_:_:)"
---

# AudioDeviceStart(_:_:)

## Declaration

```swift
func AudioDeviceStart(_ inDevice: AudioObjectID, _ inProcID: AudioDeviceIOProcID?) -> OSStatus
```

## Parameters

- `inDevice`: The AudioDevice to start the IOProc on.
- `inProcID`: The AudioDeviceIOProcID to start. Note that this can be NULL, which starts the hardware regardless of whether or not there are any IOProcs registered. This is necessary if any of the AudioDevice’s timing services are to be used. A balancing call to AudioDeviceStop with a NULL IOProc is required to stop the hardware.

## Return Value

Return Value An OSStatus indicating success or failure.

## Discussion

Discussion Starts IO for the given AudioDeviceIOProcID.

## See Also

### Functions

- [AudioConvertHostTimeToNanos(_:)](coreaudio/audioconverthosttimetonanos(_:).md)
- [AudioConvertNanosToHostTime(_:)](coreaudio/audioconvertnanostohosttime(_:).md)
- [AudioDeviceCreateIOProcID(_:_:_:_:)](coreaudio/audiodevicecreateioprocid(_:_:_:_:).md)
- [AudioDeviceCreateIOProcIDWithBlock(_:_:_:_:)](coreaudio/audiodevicecreateioprocidwithblock(_:_:_:_:).md)
- [AudioDeviceDestroyIOProcID(_:_:)](coreaudio/audiodevicedestroyioprocid(_:_:).md)
- [AudioDeviceGetCurrentTime(_:_:)](coreaudio/audiodevicegetcurrenttime(_:_:).md)
- [AudioDeviceGetNearestStartTime(_:_:_:)](coreaudio/audiodevicegetneareststarttime(_:_:_:).md)
- [AudioDeviceStartAtTime(_:_:_:_:)](coreaudio/audiodevicestartattime(_:_:_:_:).md)
- [AudioDeviceStop(_:_:)](coreaudio/audiodevicestop(_:_:).md)
- [AudioDeviceTranslateTime(_:_:_:)](coreaudio/audiodevicetranslatetime(_:_:_:).md)
- [AudioGetCurrentHostTime()](coreaudio/audiogetcurrenthosttime().md)
- [AudioGetHostClockFrequency()](coreaudio/audiogethostclockfrequency().md)
- [AudioGetHostClockMinimumTimeDelta()](coreaudio/audiogethostclockminimumtimedelta().md)
- [AudioHardwareCreateAggregateDevice(_:_:)](coreaudio/audiohardwarecreateaggregatedevice(_:_:).md)
- [AudioHardwareDestroyAggregateDevice(_:)](coreaudio/audiohardwaredestroyaggregatedevice(_:).md)