General Antonyms:
* Shout: This is a strong contrast to a quiet murmur.
* Roar: Similar to shout, but even louder and more powerful.
* Declaim: To speak loudly and forcefully, often in a formal setting.
* Boast: To speak with arrogance and pride, usually about oneself.
* Proclaim: To announce something loudly and publicly.
Antonyms related to sound:
* Silence: The complete absence of sound.
* Loud: The opposite of a soft murmur.
* Clamor: A loud and confused noise.
Antonyms related to meaning:
* Agree: If someone is murmuring disagreement, the antonym would be to agree.
* Praise: If someone is murmuring criticism, the antonym would be to praise.
To choose the best antonym, consider the following:
* The context of the sentence: What is being murmured about?
* The tone of the murmur: Is it a quiet complaint, a whisper of agreement, or a soft, affectionate sound?
For example, if someone is murmuring disapproval, a good antonym might be praise. However, if someone is murmuring a secret to a friend, the antonym could be shout.