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# kAudioFormatParameterValueStream

A key that specifies the A side-chain of float 32 data that an audio unit provides for sending high-density parameter value control information, and uses no flags.

```
var kAudioFormatParameterValueStream: AudioFormatID { get }
```

## Discussion

An audio unit typically runs a parameter value stream at either:

- The sample rate of the audio unit’s audio data.
- An integer quotient such as a half or a third of the sample rate of the audio.

The [`mSampleRate`](/documentation/CoreAudioTypes/AudioStreamBasicDescription/mSampleRate) field in the [`AudioStreamBasicDescription`](/documentation/CoreAudioTypes/AudioStreamBasicDescription) structure describes this relationship.

---

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