There are different ways of pausing an audio call depending on the operating sistem of your device.
On Android (screenshot on the left), accepting a GSM call on your device while you are on a call with EnigmediaApp, will put your contact on hold.
On iOS (screenshot on the right), there are different scenarios where an EnigmediaApp call may be placed on hold. All of them depend on audio interruption and may be triggered by GSM calls or alarms.
Your contact will be put on hold as long as your GSM call lasts (Android and iOS) or while your alarm rings (iOS), but your contact will not hear you and you will not hear him.
While on hold, your contact will listen to waiting music and it will be displayed a Call on hold indicator in both screens, yours and your contact's. Once the interruption is finished, EnigmediaApp's call will be automatically resumed.