All communication is an experience of your own beliefs. This doesn't mean other entities (people, cats, dogs, etc.) don't exist, it means your experience of communicating with them takes place within your own mind. What you are calling "their communication to you" is actually a complex type of self-communication. "Others" aren't totally disconnected from you or else you would have no observation of them; thus, the randomness factor of what happens in your reality doesn't negate the self-experience factor. Even the human body does unexpected things. Time is a kind of dimensional mirror, and what you perceive within time is always a reflection of you. This is physiologically demonstrated by you only experiencing your own nervous system. All forms of communication are fundamentally self-communication. Here is a simple exercise that demonstrates this concept:
Does this symbol mean something to you?
How about this symbol?
Generally Observed Phenomena
Anything and everything you observe is your unique, personal, experience of observation. The two symbols above are empirically meaningless symbols unto themselves. For you, they can mean anything you want them to. The rainbow spectrum font color was intended to symbolize the spectrum of beliefs you identify with at any given moment. That concept most likely didn't register to you when you initially saw it, which shows how the intention of one observer and the observation of that intention by another can be interpreted very differently.
When you perceive any physical symbol at all, by definition, you are experiencing the meaning you give it. The symbol only exists as the experience you have of it.
In the above example, both symbols contain the exact same letters, yet rearranging them a bit created a drastically different experience of information/belief.
Reading, Writing, Talking, and Hearing
At this very moment, you are experiencing your own beliefs about what you believe to be "reading." All letters and all words are meaningless symbols that activate certain consensus belief systems. The things that people say are literally just noises coming out of their mouth. Empirically, there is no difference between chicken scratches and the very words you are now reading—they are just symbols. When you read anything, you are shifting your perspective of what you automatically believe your reality to be, in a way which allows you to have an experience colloquially called "reading." All the information is already within your consciousness, the symbols are merely giving you a way to consciously "see" what is already unconsciously contained within you. The symbol gives you awareness of ideas you already had in your imagination, but had no relevance until you observed that particular symbol of it.
Physical contact, such as someone shaking your hand, is also an experience of self. The concept of "events taking place physically," is the result of a mental perspective. It's still an experience of the mind, coexisting with a commensurate brain state. Just because you don't know what others in your reality are doing doesn't mean that you aren't fundamentally experiencing yourself. The experience of randomness and unpredictability is just as much an experience of self as any other experience. Physical forms of communication are literally an embodiment of the paradox that is physical reality: it's all just you, having the real experience of "others." Someone giving you a hug is no more an expression of physical self-communication as you saying "I love you" to yourself; they are obviously not equivalent, and not as equally fun, but they are nevertheless both expressions of self-communication, just in different formats.
What you experience as information and communication is only your perspective. Someone may read the statements above and feel enraged; someone else might feel gratefully entertained. The perspective one chooses, consciously or unconsciously, is the perspective they will experience as their truth.