emit

Compared meaning: to produce a sound (verb).

比较义项：发出声音（动词）。

• utter

  Used for a person (or animal) producing a vocal sound or speaking words, often in phrases like 'utter a word/cry'; more formal and literary in tone.

  指人（或动物）发出声音或说出话语，常用于“utter a word/cry”这样的短语；语气较为正式、文学化。

  She was too frightened to utter a single word.

  她吓得说不出一个字。

• emit 本词

  Used for objects, machines, or devices giving off a sound (or other emission like light or gas); neutral, often technical register, commonly followed by 'a sound' or a specific noise.

  指物体、机器或设备发出声音（或其他散发物，如光、气体）；语气中性，常用于较技术性的语境，后面常接“a sound”或具体的声音描述。

  The machine began to emit a loud humming sound.

  这台机器开始发出响亮的嗡嗡声。

Both words mean to produce a sound, but the subject differs. Utter is for a person or animal speaking, as in 'utter a word', and formal. Emit is for objects or machines giving off a sound, neutral and technical. Utter can mean 'complete', not compared.

这两个词都可以表示“发出声音”，但主语和语气不同：utter 多用于人（或动物）开口说话或发出叫声，语气较正式、文学化；emit 多用于机器、设备等物体发出声音，语气中性偏技术性。这里不比较 utter 作形容词时表示“完全的”的用法（如 utter nonsense）。