Silence is the relative or total lack of audible
Hearing (sense)
Hearing is the ability to perceive sound by detecting vibrations through an organ such as the ear. It is one of the traditional five senses...

Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...

. By analogy, the word silence may also refer to any absence of communication
Communication is the activity of conveying meaningful information. Communication requires a sender, a message, and an intended recipient, although the receiver need not be present or aware of the sender's intent to communicate at the time of communication; thus communication can occur across vast...

, even in media other than speech
Speech is the human faculty of speaking.It may also refer to:* Public speaking, the process of speaking to a group of people* Manner of articulation, how the body parts involved in making speech are manipulated...

Silence is also used as total communication, in reference to non verbal communication and spiritual connection. Silence is also referred to no sounds uttered by anybody in a room and or area. Silence is a very important factor in many cultural spectacles, as in rituals.

In discourse analysis
Discourse analysis
Discourse analysis , or discourse studies, is a general term for a number of approaches to analyzing written, spoken, signed language use or any significant semiotic event....

, brief absences of speech mark the boundaries of prosodic unit
Prosodic unit
In linguistics, a prosodic unit, often called an intonation unit or intonational phrase, is a segment of speech that occurs with a single prosodic contour...

s used by speakers.

Be silent always when you doubt your sense.

Alexander Pope

Be silent as to services you have rendered, but speak of favours you have received.

Seneca the Elder

But my words like silent raindrops fell, and echoed in the wells of silence.

Paul Simon, The Sound of Silence

“Do not too hastily conclude that silence is indifference. Indifference is not to care, not to act, not even to think or breathe. Indifference is inhuman and inhumane. Silence, on the other hand, is almost always premeditated, a willful act. Without silence there would be no sound.”

Justin Bryan Snider

Heard melodies are sweet, but those unheard Are sweeter: therefore, ye soft pipes, play on

John Keats, Ode on a Grecian Urn

"If you do not understand my Silence, how will you understand my Words."

Author Unknown

In human intercourse the tragedy begins, not when there is misunderstanding about words, but when silence is not understood.

Henry David Thoreau

In the end, we will remember not the words of our enemies, but the silence of our friends.

Martin Luther King, Jr.

It is a great thing to know the season for speech and the season for silence.

Seneca the Elder

It was after I got to Boston that I went into the anechoic chamber at Harvard University. Anybody who knows me knows this story. I am constantly telling it. Anyway, in that silent room, I heard two sounds, one high and one low. Afterward I asked the engineer in charge why, if the room was so silent, I had heard two sounds. He said, 'Describe them.' I did. He said, 'The high one was your nervous system in operation. The low one was your blood in circulation.'

John Cage