A Traditional Landline Telephone System Mainly Contains Below Three Parts:
1. A Hook Switch, Which Connects And Disconnects The Phone From The Network;
2. A Speaker, Which Can Be Used Without Picking Up a Handset And Several People Can Participate In a Call At The Same Time;
3. A Microphone, Through Which Sound Waves From Your Voice Compress And Decompress The Granules, Changing The Resistance And Modulating The Current Flowing Through The Microphone.
USA CES Show 2019
HK Electronics Fair (Autumn Edition) 2018