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

# backgroundNoise

An estimated timeseries of ambient noise intrusion.

## Declaration

```swift
let backgroundNoise: Double
```

## Discussion

Discussion The sensor’s estimate of ambient noise intrusion in the normalizedReflectance signal (Normalized Units).

## See Also

### Accessing noise terms

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