The young's modulus of human eardrum at high strain rates

The mechanical behavior of human eardrum has been investigated extensively under low frequency or quasi-static loading conditions. However, the eardrum is actually used in auditory frequency range between 100 and 20,000 Hz, corresponding to the behavior at high strain rates. The mechanical properties such as Young's modulus data at high frequency are important to model the acoustic transmission in human ear. In this study, a miniature split Hopkinson tension bar (SHTB) was used to load a small eardrum strip specimen (1.5 mm × 4.5 mm) in either radial or circumferential direction at high strain rates. We present the experimental data for the Young'sm modulus of normal human eardrums in both circumferential and radial directions at high strain rates. Results indicate that the Young's modulus has a strong dependence on strain rate, and there exists a difference in Young's modulus in the radial and circumferential directions at strain rates up to ∼750 s^-1, but the difference vanishes at strain rate ∼1350 s^-1, showing nealy isotropic in-plane mechanical behavior at this strain rate.