Microphone

A microphone was a piece of technology meant to amplify voice. The Eleventh Doctor described them as amplifying one's natural abilities. (TV: Hide) Microphones were also used for communication purposes. (TV: The Dalek Invasion of Earth etc.)

Vicki Pallister speaks into a microphone. (TV: The Rescue)

Microphones were used by singers as early as the 1940s. (TV: The Empty Child)