Spanish preserved Latin *vox* almost intact as *voz*; English received it softened through French — the same root wearing two accents. Chinese refuses this inheritance entirely: 声音 joins striking-sound with resonant tone, making voice an event at the ear rather than a faculty of the mouth. Esperanto's *voĉo*, built from Romance shards by Zamenhof, arrives already knowing its ancestors. None of the four quite locates what voice is: not breath, not sound alone, but the one signal a listener cannot attribute to anyone else.
Entered Middle English via Anglo-Norman and Old French voiz, displacing native Old English stemn/stefn (cognate with German Stimme). The French detour explains the phonological divergence from Spanish voz despite their shared Latin root.
Direct Castilian reflex of Latin vox, vocis with regular consonant shift. The plural voces preserves the Latin genitive stem vocis, making the Latin ancestry legible in everyday grammar.
The traditional 聲 depicts a stone chime being struck (殸) while an ear (耳) receives the sound — voice as physical event: vibration made, vibration perceived. The simplified 声 preserves the gesture of striking but loses the ear, leaving only the action without the listener.
音 is 言 (speech) with an extra mark inside the mouth-component, traditionally read as the moment articulation acquires sustained tone — when words become music, or when sound takes on a pitch that makes it recognizable.
声音 covers both 'voice' and 'sound/noise' in general. For unambiguously human voice, speakers may use 嗓音 (sǎngyīn, throat-sound) or 人声 (rénshēng, human-sound). Context typically disambiguates.
Zamenhof coined voĉ- from Romance sources; the ĉ (/tʃ/) most likely reflects Italian voce specifically, though French voix and Spanish voz were also in his linguistic environment. The -o suffix is the universal Esperanto noun marker.
A voice is not what the mouth makes — it is the one sound the ear cannot mistake for anyone else's.