异口同声 (yì kǒu tóng shēng)

different mouths, same voice; to speak in unison (idiom)

Character breakdown

异 (yì) · 6 strokes

Phonosemantic compound. 廾 represents the meaning and 已 represents the sound. Simplified form of 異. Based on the original meaning "carry on the head", now written as 戴. The current meaning is a phonet…
口 (kǒu) · 3 strokes

Pictograph of a mouth.
同 (tóng) · 6 strokes

Depicts a large object (凡) like a shoulder carriage that requires the cooperation of multiple people working together to carry.
声 (shēng) · 7 strokes

Remnant of the character 殸 (stone chimes). Depicts a musical stone chime hung up on a rope. Simplified form of 聲.

大家异口同声地回答了问题。
different mouths, same voice; to speak in unison (idiom)
dà jiā yì kǒu tóng shēng dì huí dá le wèn tí 。