This article summarizes the major historical efforts used in the evaluation of the adult human middle-ear system that fall under the heading of “acoustic immittance”. The authors’ goal is to provide a historical overview of middle-ear measurement and introduce wideband tympanometry (referred to as wideband acoustic immittance in this paper). Historically, middle-ear measurement has progressed from the use of ambient-pressure systems in the absence of an acoustic reflex, to the use of systems designed to measure immittance changes over pressure variations for a single frequency probe, and finally, to an extension of the latter implementation but with the use of discrete multi-frequency probes thereby advancing the ability to diagnose diseases of the middle-ear. Wideband tympanometry is the latest in a series of developments of middle-ear assessment and expands upon the multi-frequency approach by offering a greater range and finer resolution across the frequency domain. This enhancement thus furthers the advancement of characterizing middle-ear function and diagnosing middle-ear pathology. The Titan has developed an advanced commercially available platform capable of measuring wideband tympanometry and absorbance.