Fariborz Alipour - The University of Iowa
Ronald Scherer - The University of Iowa

In this study, three methods of turbulence averaging to obtain the deterministic signal and the turbulence portion of the glottal jet were examined. These methods were smoothing, ensemble averaging, and wavelet de-noising. Ensemble averaging results in a deterministic signal that disregards gross cyclic alterations while exaggerating the turbulence intensity. Wavelet de-noising is problematic in knowing which levels of analysis to choose to represent both the deterministic and turbulence appropriately. Smoothing appears to be the most appropriate for phonation velocities because it preserves gross cyclic variations important to perturbations and modulations, while extracting turbulence at what appears to be reasonable levels.

Turbulent Flow – Pulsatile Jet – Excised Larynx – Wavelet