Summary of: Rosowski, J. J., Stenfelt, S., & Lilly, D. (2013). An overview of wideband immittance measurements techniques and terminology: you say absorbance, I say reflectance. Ear and hearing, 34 Suppl 1(0 1), 9S–16S. https://doi.org/10.1097/AUD.0b013e31829d5a14
This article reviews the relationship between acoustic immittance, and pressure and power absorbance. While pressure absorbance is dependent upon the immittance at the tympanic membrane (TM), the area of the cross-sectional plane of the ear canal, and the distance between the probe location and the TM; power absorbance only depends upon the former two attributes and is independent probe location, which is an advantage of power absorbance. However, because power absorbance is not sensitive to probe location and thus void of the resultant phase information, it lacks the ability to identify sources of error, e.g., acoustic leaks, and fully describe the mechanics and acoustics at the TM. The authors state that the middle ear is best described by combining absorbance, and impedance magnitude and phase. The Titan offers a complete measurement platform capable of calculating absorbance, and the impedance magnitude and phase and thus stands as an advanced comprehensive diagnostic middle-ear device.