Test Tone Waveforms

The test tone files shared by Carl can be used to illustrate the capabilities of the free, cross-platform audio editing program Audacity. Below is a screen shot showing the 3 individual tone waveforms and the composite waveform, as displayed in the program. The tones were of 30-second duration, but this display is zoomed in to about .06 second to make the waveform shapes clearly visible. Click on the image to enlarge.

Audacity also has a frequency analysis tool that produces a plot of amplitude vs. frequency for up to 23.8 seconds selected from a waveform. Below is a screen shot showing the analysis of the composite waveform, with the 3 peaks corresponding to the individual notes (C, E, G) or frequencies contained in the composite. Click on the image to enlarge.

This program, like others of its kind, enables a user to record audio entering a PC's sound card, and to perform edits on all or portions of a recording. Such simple edits as copy/cut & paste, and amplitude changes can be done with the same ease as their equivalents in a word processing program. Many other editing functions are included.