I can't hear the voice when I send a message, and I can't see the expression when I call.

you can't hear the voice when you send a message, and you can't see the expression when you make a phone call. There must be no voice when you send a message, because we send words, but we can choose to send voice so that we can hear it. You can't see the expression when you make a phone call, because we can choose to open a video so that we can see it.