“This article shows you how to make a transistor microphone amplifier.
The minimum power supply for this circuit is 1.5 V. However, you will need at least 3 V if you are making an optional LED detector (transistor Q3) and want your LED to turn ON.
The signal from the microphone is amplified by transistor Q1 and Q2 before applied to Q3 transistor for detection.
You can see my circuit working in the video.
I thought of this idea after reading this article:https://www.instructables.com/id/Ultrasonic-Alien/
Supplies:Components: cheap microphone - 2, general-purpose transistors - 5, 100 ohm high power resistor - 5, 1 kohm resistor - 1, 10 kohm resistor - 10, 470 uF capacitor - 10, 220 kohm resistor - 2, 470 nF capacitor - 5, matrix board, insulated wires, 1 mm metal wire, 1.5 V or 3 V power source (AAA/AA/C/D batteries), 1 Megohm to 10 Megohm resistor pack.
Tools: pliers, wire stripper
Optional components: solder, LEDs - 2, battery harness.
Optional tools: soldering iron, USB oscilloscope, multimeter.”