Context: In 1957, Braunstein further demonstrated that the rudimentary devices could be used for non-radio communication across a short distance. As noted by Kroemer Braunstein".. had set up a simple optical communications link: Music emerging from a record player was used via suitable electronics to modulate the forward current of a GaAs diode. The emitted light was detected by a PbS diode some distance away. This signal was fed into an audio amplifier, and played back by a loudspeaker. Intercepting the beam stopped the music. We had a great deal of fun playing with this setup." This setup presaged the use of LEDs for optical communication applications.

Question: What year was it discovered that early LED instruments could be used for non-radio communication?
Answer: 1957

Question: Who discovered non-radio uses for early LED devices?
Answer: Kroemer Braunstein

Question: The current in non-radio communication had to go through what type of component?
Answer: a GaAs diode

Question: What other component was needed to detect the first current of a non-radio signal?
Answer: a PbS diode

Question: What final device was needed to hear the signal from the initial GaAs diode?
Answer: audio amplifier

Question: What year was it discovered that early LED instruments could be used for radio communication?
Answer: Unanswerable

Question: Who discovered radio uses for early LED devices?
Answer: Unanswerable

Question:  The current in radio communication had to go through what type of component?
Answer: Unanswerable

Question: What other component was needed to detect the second current of a radio signal?
Answer: Unanswerable

Question:  What first device was needed to hear the signal from the initial GaAs diode?
Answer: Unanswerable