Distribution of thetaY226 in a clinical population

ThetaY (thetaY) is the phase angle between the admittance vector and the conductance component in an acoustical system. It is determined by the relative contributions of the system's conductance and susceptance. The magnitude of the admittance vector has received almost exclusive attention in clinical admittance measurements. The phase angle, providing information on the relative contribution of energy-dissipating and energy-storing components, has been largely overlooked. One hundred and ninety-five clinical records obtained over a five-year period were used to investigate the distribution of thetaY and its relationship to other tympanometric variables. The results show that thetaY has a reasonably symmetrical distribution and is not strongly related to other tympanometric variables. The data suggest that thetaY may account for a different subset of the total variance than more commonly measured variables. ThetaY appears to meet the criteria of independence and distribution, justifying further study to evaluate its clinical utility.