SigJenny turns your PC into a flexible and powerful signal generator. It creates numerous different waveshapes whilst showing graphically both the output and the response from a microphone. The square and triangular signals can have their mark/space ratio continuously altered to make sawtooth and pulse waveforms and all signals can be inverted. Output can be a single frequency or swept, or a single or repeating tone burst. The latest version has a quicker and more general calibration process.