Sony Xperia1 IV User Manual page 126

In-Call Screen Layout/In-Call Operations
1 Appears for calls with HD Voice, and
9/47
Phone
①
Show image registered for contact
②
Show name/number registered for
other party
③
Appears for high-quality sound
calls
1
④
Show dialing screen and send push
signals during call
⑤
Mute your voice to the other party
⑥
Add call
⑦
Show call time
⑧
Call using Speaker/Bluetooth
device
⑨
Place call on hold
⑩
Record call
⑪
End call
for calls with VoLTE (HD+).