(1) A fundamental term used in the phonetic classification of speech sounds, referring to the auditory result of the vibration of the vocal folds. Sounds produced while the vocal folds are vibrating are voiced sounds, e.g. [b, z, a, i]; those produced with no such vibration are voiceless or unvoiced, e.g. [p, s, h]. A sound which is normally voiced, but which in a particular phonetic environment is produced with less voice than elsewhere, or with no voice at all, is said to be devoiced (symbolized by a small circle beneath the symbol) - examples are the reduced voicing on voiced plosives in a word-final position as in bib, bed [b?b], [bed].
(2) A category used in the grammatical description of sentence or clause structure, primarily with reference to verbs, to express the way sentences may alter the relationship between the subject and object of a verb, without changing the meaning of the sentence. The main distinction is between active and passive, as illustrated by The cat bit the dog and The dog was bitten by the cat: in the first sentence, the grammatical subject is the goal of the action - it is ‘acted upon’, and thus ‘passive’. There will be certain differences in the emphasis or style of these sentences, which will affect the speaker’s choice, but the factual content of the two sentences remains the same. In other languages, further contrasts in voice may be encountered, e.g. the ‘middle’ voice of Greek (which included verbs with a reflexive meaning, e.g. She cut herself), and there are several other types of construction whose role in language is related to that of voice, e.g. ‘reflexive’, causative, ‘impersonal’ constructions. Voice contrasts may be formally marked in the verb (e.g. by inflection, word-order or the use of special auxiliaries), or elsewhere in the sentence (e.g. by the use of passive ‘agent’); the English passive can involve all three factors, as in I was kicked by a bull.
（2）對句子或小句結構作語法描寫的一個范疇，主要與動詞相關，表達句子改變動詞的主語和賓語之間的關系而又不改變句子意義的方式?！皯B”主要分主動態和被動態，例如The cat bit the dog“貓咬狗”和The dog was bitten by the cat“狗被貓咬”：前一句的語法主語同時是動作者；第二句的語法主語是動作的目標，是“動作的對象”，因此是“被動的”。這兩個句子在強調重點和風格上有所差別，這會影響說話人的選擇，但在事實內容上兩個句子相同。其他語言中還可能見到其他的態，例如希臘語有“中間”態（包括帶反身意義的動詞，如She cut herself“她割她自己”），而且有多種其他構式在語言中的作用跟這種形態有關，例如“反身式”、使役式、“無人稱”構式等。態的對立可由動詞帶形式標記表示（例如屈折形式，詞序或使用特殊的助動詞），也可由句子其他部分表示（例如用被動“施事”）；英語被動態可能同時涉及上述三個因素，如I was kicked by a bull“我被一頭公牛踢了一腳”。