Part of the AudacityForBlindUsers section of the Wiki.
Unfortunately, Audacity 1.2.2pre does not yet implement the Nyquist pan command (why not?). That would make panning _much_ easier for keyboard-only use.
Until pan is implemented, here's a keyboard-only work-around:
1. Have a mono sound open in Audacity;
2. With numlock off, move the cursor until it's sitting on 'audio track' (or the name of the file you've opened). You can use the up and down arrows on the numeric keypad to do this (8 and 2, respectively);
3. press the / button on the numeric keypad (equivalent to the left mouse button);
4. Press 'l'. This will move the audio to the left channel;
5. Select all using control-a;
6. Open the effects menu with alt-c;
7. Press 'n' until you get to 'Nyquist prompt';
8. In the edit box, type:
(mult s 0.8)
(the number should be between 0 and 1; the higher the number, the louder the signal will be. It's a linear not db number.) 'Mult' means multiply the audio s by the given number. 0 will reduce the volume to zero, 1 will create no change, something above 1 will increase the volume;
9. Export (save) the file using alt-f, 'e', hit the enter key, type the name of the file and click on the 'save' button. (You may need to specify the folder);
10. Press control-z twice to undo the amplification (mult) and channel-select jobs;
11. Repeat the above steps 2 through 10, except choose 'r' to move the audio to the right channel, and use a number which added with the first number totals 1.0. For this example, in the Nyquist prompt type:
(mult s 0.2)
12. Press control-i to import the wav file you first saved (which is in the left channel; type the name of the file you saved in the edit box; you may need to type the folder too);
13. The audio will be somewhere in the stereo field between the far left and far right channels. Using the example numbers, the audio will sound somewhere left of center.
You'll probably need to do some experimenting to get the desired panning placement just where you want it.