Noise is anything that is unwanted but interferes within the communication process ultimately reducing the quality or effectiveness of a successful communication. This interference (i.e. noise) can take place on the Speaker's (Source) side, or on the Listener's (Receiver) side, or it can happen somewhere in between.

There are 4 types of communication noise. These are:

1. Physical: physical noise is any sort outside interferences caused by someone or something. Example of this type of noise is a loud sound of an aircraft, or a vehicle on the street, or loud music being played nearby. This type of noise include any such thing that takes place outside the ongoing conversation. Physical noise is an external interference that takes place outside both the Source and the Receiver, and it disturbs the physical transmission of the signal or message.

2. Psychological: psychological noise refers to the different biases and predispositions people have beforehand engaging in a communication with someone that can unconsciously shape how they interpret messages. For example, if 'Person A' has prior information that 'Person B' is a bad person, no matter how the interaction among them goes, 'Person A' is highly likely to decide that 'Person B' is not good. Another example is, also, when people have some biases, or prejudices, they do not communicate open-mindedly and usually stick to their prior decisions. This happens because when we communicate with someone with ideas about how the person is or what the other person is going to say and why, we focus more on our pre-assumptions and ignore the original message given by the person. Psychological noise is also referred to as 'mental interference' in the speaker or listener. Being inattentive or having wandering thoughts during a conversation is also psychological noise.

3. Physiological: physiological noise is any sort of physiological or biological or other physical disturbances that negatively interfere with people's ability to communicate effectively. Examples are loss of vision, loss of hearing, or sickness etc. that create obstructions in communicating effectively. Physiological noise is created by barriers within the Source or the Receiver that also include articulation problems, mumbling, talking too fast or too slow etc.

4. Semantic: semantic noise is the interference or hindrance created usually by the psychological gap between the Source and the Receiver. If the psychological construct of the Source differs from that of the Receiver, then the encoding and decoding of the message gets adversely affected for both ends. An example of this can be: if a Science Professor is lecturing on astrophysics or hydrodynamics, it is likely that a humanities student will not be able to make any sense of it; on the other hand, a science student may not understand a word from a lecture on rhetoric. Semantic noise is actually caused by the Source (i.e. the encoder). If the Source uses technical language or phrase or jargons that are unfamiliar to the Receiver (the decoder), the Receiver will not be able to understand the message because of 'semantic' noise. Abstract ideas or connotations are also able to create semantic noise.

References

Beauchamp, Susan R. & Baran, Stanley J. (2015). Introduction to Human Communication: Perception, Meaning, and Identity.
Oxford University Press. ISBN-10: 0190269618, ISBN-13: 978-0190269616.
European Commission. The Green Paper on Future Noise Policy.
Rothwell, Dan J (2004). In the Company of Others: An Introduction to Communication. New York: McGraw Hill.