How many letters does the top answer for “produced without vibration of the vocal cords” have?

The most common answer is surd (4 letters).

Crossword clue: produced without vibration of the vocal cords

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

surd 4 letters wn-def

a consonant produced without sound from the vocal cords

produced with vibration of the vocal cords 80% similar → sonant, voiced

speaking softly without vibration of the vocal cords 57% similar → susurration, whisper, whispering