---
title: shimmer
framework: speech
role: symbol
role_heading: Instance Property
path: speech/sfvoiceanalytics/shimmer
---

# shimmer

The variation in vocal volume stability (amplitude) in each frame of a transcription segment, expressed in decibels.

## Declaration

```swift
@NSCopying var shimmer: SFAcousticFeature { get }
```

## See Also

### Analyzing voice

- [SFAcousticFeature](speech/sfacousticfeature.md)
- [voicing](speech/sfvoiceanalytics/voicing.md)
- [pitch](speech/sfvoiceanalytics/pitch.md)
- [jitter](speech/sfvoiceanalytics/jitter.md)