How we change what others think, feel, believe and do
Every medium is an extension of our senses or body parts and can change the way we view the world (e.g. the effects of the internet). Media affects us differently, according to their fidelity (or form).
High fidelity, hot media
High fidelity media send messages that are complete, requiring little extra interpretation. They are clear and easy to understand.
Their ease of interpretation allows listeners to easily fall into the encompassing environment that may be produced. On the other hand, the lack of effort required by the person involved may reduce their engagement. A high fidelity medium in which the person does become engaged, perhaps through interest in the subject-matter, is highly effective.
A high fidelity medium is also known as a 'hot' medium.
Low fidelity, cool media
Low fidelity media send messages that are incomplete, requiring the person involved to put noticeable effort into assimilating the message.
Low fidelity need not be low value, but the composer does need to think more about how to engage the target audience. With care, the low fidelity may be turned to one's advantage, perhaps using it to suggest and tease.
A low fidelity medium is also known as a 'cool' medium.
Phones are low fidelity, as they do not give full-spectrum sound and do not include a visual element to communications. You need to concentrate to fully hear the message.
Movies are high-fidelity, as they block out all other images and include sound (often surround-sound). Thus they engage their audiences and can easily get them to suspend reality.
Cartoons may be considered as low fidelity as they use simple lines and leave out a lot of detail. They may still be engaging, perhaps through the use of humor.
Marshal McLuhan is famed for saying 'The medium is the message', thus emphasizing the importance of media.
In McLuhan's day, far more was low fidelity than today. Records were scratchy, television was grainy, newspapers were black and white (but read all over :-).
Marshal McLuhan, Understanding Media: The Extensions of a Man, NY: Signet Books, 1964