system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: You know the arrow on the car signaling your next turn? Where does the sound come from and how does it make it?
gpt
Originally it came from a solenoid switch, a switch activated by an electromagnet. The current would make a magnetic field to close the circuit and light the signal, creating a clicking noise behind the dashboard.

These days the sound is expected as feedback that the signal is activated and it is produced by a speaker or in some cases a solenoid switch that isn't connected to anything.