Intercom is useful circuit that keeps you in touch with your family member present in another room without moving from your place. You can mount this circuit in outside area of your house like in garage, and you can this circuit for bidirectional communication.This circuit is based on IC LM 386 Working of the circuit is very simple first we have to adjust its gain factor through pin 1 and 8 if it is left open the gain will be 20 as it is internally set in IC but it can be vary by adding a resistor and a capacitor up to 200. Now feed the required signals to pin 2 or 3. A resistor is connected to pin 3 to adjust the sensitivity of input signal and we will get output on pin 5.