Noise is anything that interferes with a message being transmitted from a sender to a receiver. It results from both internal and external factors.
Communication scholars classify four types of noise: physical, psychological, physiological and semantic.
Physical noise is external to the speaker and listener. It includes things such as the sounds of road construction outside your window that make it difficult to hear what is being said.
Psychological noise is mental interference that prevents you from listening. If your mind is wandering when someone is speaking to you, the noise in your head is preventing communication.
Physiological noise is any physiological issue that interferes with communication. For example, if you have a migraine, it may be difficult to speak to others or listen to them when they speak to you.
Semantic noise occurs when there is no shared meaning in a communication. This often occurs when someone is dealing with medical professionals, lawyers, scientists or others who use terminology that lay people may not understand.