While listening, you can:



Touch 
When you put your phone up to your ear, the screen turns off to prevent you from accidentally touching it. To turn it back on, move it away from your ear or press the Power button.
To hide the call and use other apps, swipe up from the bottom of the screen.
To return to the call, swipe the status bar down and touch Ongoing call.
If call waiting is active and a new call comes in, you can answer it. Touch Hold and Answer Voice. The first call is put on hold.
To switch between calls, tap 
To merge the calls, tap 
Your phone doesn't come with an application for recording calls. Only certain phones and carriers, in countries or regions where call recording is supported, can record calls.
Recording a conversation without the consent of the other party is illegal in most countries. Know your country's laws before recording a call.
Tap 
If you’re having issues, try these troubleshooting steps.