The Spanish word 'voz' meaning 'voice' comes directly from the Latin word 'vox', which meant 'voice' or 'sound'. This is a straightforward evolution where the Latin 'x' changed to 'z' in Spanish, a common sound change between these languages.

Some related Spanish words include 'vocal' (vocal), 'vocear' (to shout), and 'vociferar' (to vociferate). All these words share the same Latin root 'vox' and relate to the concept of voice and sound.

English speakers might recognize the connection to words like 'voice', 'vocal', 'vocalize', and 'vocabulary', which all come from the same Latin root 'vox'. Even the word 'vowel' is related, as it refers to sounds made by the voice without obstruction. This shared Latin heritage explains why 'voz' and 'voice' are so similar in both form and meaning.