Radio
From Tardis Wiki, the free Doctor Who reference
Radios are simple devices used to relay or receive sound over a short distance using radio waves. They are useful for communicating on a planetary level but not on a solar scale because the time delay becomes greater the further a target is removed. Most civilizations stop using radios when they move into space.
Alternatively; the name radio can also be used to describe any device that is capable of transmitting or receiving sound.
