Abstract: Tympanometric apparatus comprises a housing of two tubular parts (10, 11) interconnected in a T-shape, a first part (10) having an eyepiece (13) and a speculum (12) at its opposite ends, a semi-silvered or dielectric mirror (14) between the ends, and light and sound sources (15, 16) between the mirror and speculum, and the other housing part (11) having a photodetector (19) across a small area thereof and focusing means (22) between this and the first housing part, the light source projecting a beam through the speculum for reflection from a tympanum to be examined, this reflection being partly transmitted through the mirror to the eyepiece and partly reflected again to be focused on the photodetector, and the sound source causing oscillation of the tympanum with consequent variation of the reflection path and photodetector output. Preferably a microphone (23) is also carried by the first housing part to monitor the acoustic pressure adjacent the tympanum.