Communication channel:
The communication channel is the physical medium through which the sender's message is transmitted to the receiver. Air is the most common physical means of communication. Other channels used are, for example, the telephone, the cell phone, the electronic mail, the voice, among others.
Noise:
Noise is any signal that distorts the original message that the sender wants to transmit. The noise can be environmental, channel, emitter, message or receiver.
It is important to know where the noise in the communication comes from so that it can be reduced or eliminated to create a clear and effective communication process.