Apple releases v3.7.2 for AirPods 

Today Apple released a software update for AirPods. According to the German-language publication (Google Translate), which first spotted the new firmware, Apple is believed to have addressed the reported Bluetooth connectivity issues where AirPods would lost connection with their paired iPhone during phone calls.

To check your AirPods firmware go to your iPhone and select Settings, General, about then open your AirPods case swipe away the pop up menu then you will see AirPods firmware information.