---
title: attenuationDurationThresholds
framework: exposurenotification
role: symbol
role_heading: Instance Property
path: exposurenotification/enexposureconfiguration/attenuationdurationthresholds
---

# attenuationDurationThresholds

The configurable signal-loss thresholds for calculating exposure risk.

## Declaration

```swift
var attenuationDurationThresholds: [NSNumber] { get set }
```

## Discussion

Discussion important: This property is available in iOS 12.5, and in iOS 13.6 and later. Signal attenuation and duration are measurable aspects of exposure risk. Set threshold values to configure the degree to which the signal loss between two devices for a specific duration signifies a potential exposure. Four categories are described in ENExposureConfiguration: immediate, near, medium, and other.

The following entries in the attenuationDurationThresholds array correspond to three thresholds for the four categories: Attenuation values greater than attenuationDurationThresholds[2] accumulate into the “other” category.

## See Also

### Configuring Duration

- [immediateDurationWeight](exposurenotification/enexposureconfiguration/immediatedurationweight.md)
- [mediumDurationWeight](exposurenotification/enexposureconfiguration/mediumdurationweight.md)
- [nearDurationWeight](exposurenotification/enexposureconfiguration/neardurationweight.md)
- [otherDurationWeight](exposurenotification/enexposureconfiguration/otherdurationweight.md)
- [daysSinceLastExposureThreshold](exposurenotification/enexposureconfiguration/dayssincelastexposurethreshold.md)