---
title: backgroundNoiseOffset
framework: sensorkit
role: symbol
role_heading: Instance Property
path: sensorkit/srphotoplethysmogramopticalsample/noiseterms-swift.struct/backgroundnoiseoffset
---

# backgroundNoiseOffset

The white noise variance estimate in the background noise signal.

## Declaration

```swift
let backgroundNoiseOffset: Double
```

## Discussion

Discussion This value represents the white noise variance estimate per Hz in the backgroundNoise signal (Normalized Units²/Hz). Apply the noise equivalent bandwidth factor to account for in-band noise for your setup.

## See Also

### Accessing noise terms

- [whiteNoise](sensorkit/srphotoplethysmogramopticalsample/noiseterms-swift.struct/whitenoise.md)
- [pinkNoise](sensorkit/srphotoplethysmogramopticalsample/noiseterms-swift.struct/pinknoise.md)
- [backgroundNoise](sensorkit/srphotoplethysmogramopticalsample/noiseterms-swift.struct/backgroundnoise.md)