F: Goertzel Algorithm

Abstract

The Goertzel algorithm can perform tone detection using much less CPU horsepower than the Fast Fourier Transform, but many engineers have never heard of it. This article attempts to change that. Most engineers are familiar with the Fast Fourier Transform (FFT) and would have little trouble using a “canned” FFT routine to detect one or more tones in an audio signal. What many don't know, however, is that if you only need to detect a few frequencies, a much faster method is available. It's called the Goertzel algorithm.