I've added the ability to choose the wave form when you create a single frequency or frequency set audio file. From the doc:
Wave Form is the wave form to use in creating the audio file. Pulse is the default wave, the least intense in term of magnetic power, but others are available for your experimentation. Pulse is a 5% duty positive offset only square wave. All other waves beside pulse are positive and negative offset. The next least intense wave is the Lilly wave. The other waves are sawtooth, reverse sawtooth, triangle, and sine.