Tympanometry with low-frequency probe tones provides useful clinical information for patients with disorders of the tympanum, the tympanic membrane, and the Eustachian tube. Low-frequency, single component tympanometry, however, is relatively insensitive to many lesions that affect the ossicular chain. This review focuses upon a collection of four, interrelated acoustic measurement techniques that have been developed for identification and differential diagnosis of those middle ear disorders that do not always yield pathognomonic patterns with conventional tympanometry. Specifically, the initial hypotheses, the methods, normative data and representative clinical findings are summarized for: (1) a multiple frequency magnitude array; (2) a multiple frequency phase-angle array; (3) a three-dimensional array; and (4) a differential sound pressure level and phase plot.