This is the circuit that I will use to build my project. There are other circuit that can be use to build my project, but for now I will try this circuit first. This circuit use normal component which can be found easily at any electronic store.

The components are:

- LM386 Low Voltage Audio Power Amplifier
- MPF102 Transistors
- 1K Ohm 1/4-Watt Carbon Film Resistor
- 1M Ohm 1/4-Watt Carbon Film Resistor
- 10 ohm 1/4W 5% Carbon Film Resistor
- 4.7K Ohm 1/4-Watt Carbon Film Resistor
- (x2) 0.047µF 50V Capacitor
- 220µF 35V 20% Radial-lead Electrolytic Capacitor
- 100µF 35V 20% Radial-lead Electrolytic Capacitor
- 0.1µF 50V Hi-Q Ceramic Disc Capacitor
- 10K-Ohm Linear-Taper Potentiometer
- 1/8" Mono Panel-Mount Audio Jack
- Earphone/Headphone
- 9V Battery Snap Connectors
- 9 Volt Battery
- 90dB Piezo Pulse

After I get all the components, I can start building the circuit for my project.