The Lost Word

Five words stand before you, all seemingly connected:
Library, Whisper, Whisper, Shout, Silence
One word does not belong. Can you identify it and explain why?

Solution: The outlier is "Shout." All other words share the meaning of quietness or absence of sound:
Library is a place of silence.
Whisper is a very quiet way to speak.
The word "whisper" itself is repeated, emphasizing quietness.
Silence is the complete absence of sound.
Shout, on the other hand, is the opposite of quietness and signifies a loud sound.