When you communicate, you have two responsibilities:
1. communicate your message
2. ensure the message is understood

#1 is easy – but it is #2 that counts.

You can do #1 and forget or skip #2 – but you haven’t really communicated. Saying words out loud is not communication – it’s just making noise. Communication implies an understanding from both the initiator and receiver of the communication.

You can also do #1 in such a way to make sure that #2 doesn’t happen – that’s called covering your arse.