For a personal project, I need to generate a track that contains a single, pure frequency.
My method for this involves generating a single tone using Audacity, and exporting the file. The wave stored in the file represents a pure 440Hz frequency.
I've noticed something when playing it back, though - at the end of the sample, there's a small pop. Plotting it on a Fourier transform in any of my media players reveals that this isn't just a physical effect or a problem with the sound file - it's actually a part of the file, even when recorded losslessly. Here's what it looks like on a Fourier transform:
The solid line is a 440Hz signal, but the vertical line is the end of the clip. I'm vaguely familiar with Fourier mathematics, and realize this might have to do with the boundary conditions at the end of the sound wave.
Is there a way to avoid this sharp pop at the end of the sample?