If you connect the Sony WH-1000XM5 to your smartphone, then you can use it to receive calls as well as call other people. To find out how you can control the call functionality with this wireless headset, you can take a look at this tutorial from Seeking Tech.
HFP vs. HSP for Bluetooth Calling with WH-1000XM5
In order to use call controls with the Sony WH-1000XM5, you need to use either the HFP or HSP Bluetooth profile.
With HFP (Hands-free Profile), you get more functions, when it comes to calling, compared to HSP (Headset Profile).
How to voice dial with WH-1000XM5 by using HFP
If you are using the HFP Bluetooth profile, then you can dial a number by using your voice by first pressing and holding the touch sensor control panel for 1 second. For the uninformed, the touch sensor is located on the right ear cushion.
How to cancel an outgoing call with WH-1000XM5 by using HFP or HSP
If you decide to cancel a call you are making to someone else, then you double tap the touch sensor control panel when your phone is dialing. These quick taps should be around 0.4 seconds apart. This method applies to both the HFP and HSP Bluetooth profiles.
If done correctly, the headset should stop ringing the recipient.
How to switch between your smartphone and WH-1000XM5 for outgoing calls by using HFP
If you are using the HFP profile, then you also have the ability to switch the call device from your WH-1000XM5 to your smartphone and vice versa during outgoing calls.
In order to do so, you need to press and hold the touch sensor control panel until the switch occurs.
How to answer an incoming call with WH-1000XM5 by using HFP or HSP
In order to answer an incoming call with the WH-1000XM5, you need to double tap the touch sensor control panel. This method will work for both the HFP and HSP Bluetooth connections.
How to reject an incoming call with WH-1000XM5 by using HFP
You can only reject an incoming call with your WH-1000XM5 only when you are using the HFP profile.
In order to do so, you need to press and hold the touch sensor control panel until the ringing stops.
How hang up a call with WH-1000XM5 by using HFP or HSP
Once you are done with an incoming or outgoing call, you can hang up by double tapping the touch sensor control panel on your WH-1000XM5. You can use this action on both the HFP and HSP Bluetooth profiles.
How to switch between your smartphone and WH-1000XM5 during the middle of calls by using HFP
If you are using the HFP profile, then you can also switch between your smartphone or WH-1000XM5 as the calling device during the middle of a call. To do so, you need to press and hold the touch sensor control panel of the headset until the switch occurs.