This Arduino project displays the approximate frequency of the loudest sound detected by a sound detection module. For this project, the analog output from the sound module detector sends the analog audio signal detected to A0 of the Arduino Uno. The analog signal is sampled and quantized (digitized). A Fast Fourier Transform (FFT) is then performed on the digitized data. The FFT converts the digital data from the approximate discrete-time domain result. The maximum frequency of the approximate discrete-time domain result is then determined and displayed via the Arduino IDE Serial Monitor.