1. Of course to send voice messages to friends, must be on both sides have opened the premise of IMessage. If you open a IMessage information service, but your friends are not open, or not using the IPhone, you can not send voice. When you see an icon like this, it is sent as a normal message.
2. When the IMessage typeface is displayed in the Information window, and the button icon is blue, a voice message can be sent at this time. Hold down the microphone in the lower-right corner to begin recording voice messages.
3. When we hold down the microphone icon, we can record voice messages, and we will see the voice waveform display animation. When you record a voice message, there are two options, one is to slide to X to delete not to send, and the other is to send a voice message by sliding the arrow icon.
4. The image below is the screenshot after sending the voice message, and I don't know if the test version is the reason for sending the voice message faster than the micro-letter.