Dictaphone (n.)

1650s, "authoritative utterance," from Late Latin dictationem (nominative dictatio) "a dictating, dictation," noun of action from past-participle stem of dictare  "say often, prescribe," frequentative of dicere "to say, speak" (from PIE root *deik- "to show," also "pronounce solemnly"). Meaning "act or practice of expressing orally for another to write down" is by 1727.

word-forming element meaning "voice, sound," also "speaker of," from Greek phōnē "voice, sound" of a human or animal, also "tone, voice, pronunciation, speech," from PIE root *bha- (2) "to speak, say, tell" (source also of Latin for, fari "to speak," fama "talk, report").