To edit your properties noise thresholds on the mobile app, click on the Properties tab on the bottom of the screen:
Click on the property you are looking to change the thresholds for:
Click on the Thresholds tab on the bottom of the screen:
Next you will select the sensor you are looking to change the threshold for from the dropdown menu. You can then select the NRS level and the times you want the threshold level active. To add another threshold level, click the green "+" button shown below.