selected waveform from a gaw and an acoustic signal in a complex plane or phase plane in summary the borrowed term of nyquist plot is different from conventional applications e g in control engineering rather it expresses similar concept but conveys specific information and operations in the approach described in this invention for an analysis of voice as described above the software may integrate tracing and extraction of glottal waveforms including but not limited to gaw glottal width function and vocal fold displacements with the nyquist plot and other forms of time frequency analyses of gaw including fft and short fft or spectrogram to generate quantitative and robust measures of the vocal fold vibration that correlate with the quality of the voice output vibrations of the vocal folds occur at a high frequency u2014 these vibrations may be imaged for example by using hsv which may capture images for example at 2000 frames sec alternatively the lvs which records images at only 25 frames sec and which is more commonly used in the clinic may also be utilized the application of hsv and lvs for clinical diagnosis and assessment of voice disorders is achieved through the application of automated software that extracts information on laryngeal vibrations from original laryngeal image recordings the resolution contrast and quality of which cannot always be guaranteed the various interactive or automatic methods and integrated software for high fidelity automated extraction.