Antonyms for the word "most echoing" include "least reverberating," "dampened," "hushed," and "muted." When a sound is "least reverberating," it means that the sound waves are not bouncing off surfaces, creating strong echoes. "Dampened" refers to a sound that has been absorbed or reduced by an object or material, resulting in a quieter tone. "Hushed" and "muted" both refer to sounds that are intentionally or unintentionally suppressed, resulting in a more subdued audio level. By using antonyms of "most echoing," it is possible to describe a variety of audio environments that are not characterized by an intense, reverberating sound.