This program is able to analyze sounds heard by your PalmOS device (e.g. LifeDrive), finding their frequency. Its purpose is to tune musical instruments.

Spectral Tuner is released under GNU Public License.
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How to use

After turning the program on you will usually see a black rectangle with a cyan vertical line in the middle and some blue vertical lines. When the device hears a sound, it will draw a blue graph on this background. This graph shows how much of each frequency can be found in this sound (technically, it is a graph of an approximate Fourier transform).

Before you change anything, the cyan line will correspond to the A sound. Thus, if you play the A sound, you should see a bell-like curve with the middle point exactly on the cyan vertical line. If the sound is a bit higher than A, the curve's middle point will appear to the right from the cyan line (if it is A#, it will appear on the blue line --- each blue line corresponds to a semitone). If you are trying to tune a musical instrument, this should be useful --- you will know if the sound is too low or too high, and by how much.

You can change the sound which corresponds to the cyan line by typing desired letter using your favorite input method (keyboard/graffiti). For example, if you press C, the cyan line will show the frequency of C. (The status line below the graph shows what the cyan line means at the moment.) Pressing right/left button will move the center by one semitone. Pressing x/y will move it by an octave.

You can also press numbers --- they will change the scale, i.e. how much of the spectrum will be covered by the graph. You can also do this by pressing up/down button.

Watch the number after M which is shown on the status line. It shows how loud is the sound in our frequency. If it is small, like e.g. 1, then probably your device did not hear the sound at the given moment (or its frequency is out of the covered region), and it did only hear some background noise, which is not related to the sound you are trying to tune.
If you like this program, or you have an idea to make it more useful (and maybe you want to implement it yourself), comments are welcome at longuens *at* users.sourceforge.net.