---
title: featureExtractionTimeWindowSize
framework: createml
role: symbol
role_heading: Instance Property
path: createml/mlsoundclassifier/featureextractionparameters/featureextractiontimewindowsize
---

# featureExtractionTimeWindowSize

A time duration, in seconds, that determines how much audio data the feature-extraction session reads each time it samples an audio file.

## Declaration

```swift
var featureExtractionTimeWindowSize: TimeInterval { get set }
```

## Discussion

Discussion The time-window size defaults to 0.975 seconds and must be in the range [0.5, 15.0]. Feature-extraction sessions that use MLSoundClassifier.ModelParameters.FeatureExtractorType.vggish(revision:) ignore this value and always use a time-window size of 0.975 seconds.

## See Also

### Accessing feature extraction parameters

- [overlapFactor](createml/mlsoundclassifier/featureextractionparameters/overlapfactor.md)
- [featureExtractor](createml/mlsoundclassifier/featureextractionparameters/featureextractor.md)