An experimental study of tympanic membrane and manubrium vibrations in rats

Rats are potentially very useful for auditory research because the middle ear structures are easily approachable and because rats are relatively inexpensive. The goal of the present study was to better characterize the mechanics of the rat middle ear by measuring frequency responses at multiple points on the tympanic membrane and manubrium. A laser Doppler vibrometer was used to measure the vibrations. Measurements were made on 7 rats. Tympanic membrane vibrations are presented for 7 different points in the frequency range of 1-10 kHz. The repeatability of the measurements and the interanimal variability at the umbo are also presented. The vibration modes of the tympanic membrane and manubrium were investigated.