how to set the intensity dB level of a Wav


I’m very new to Audacity and not an expert in sound designing.
I’m developing a software for a PDA which will play some pure tones
in different frequancies and Intensity dB levels.

I have already created a set of wav files with the required frequancies.
But I need to set the (adjust) the intensity dB levels of those wav files.
How can I do this with Audacity 1.2.6.

Thanx in advance