Vibratory Response of Dry Human Skulls

Abstract

Hearing loss effects millions of people of all ages and is commonly treated with hearing aids and prostheses. Bone anchored hearing prostheses use bone conduction to transmit sound through the skull bone to the functioning inner ear and cochlea, bypassing the outer and middle ear. A challenge associated with these prostheses is optimizing the location of the surgical implant. A better understanding of how vibrations travel through the skull bone will be beneficial in the improvement of current prostheses and the development of new bone conduction technologies.

Using laser Doppler vibrometry, vibration characteristics of dry human skulls were investigated. Three-dimensional vibration patterns were obtained at several frequencies and the dispersion relationship was determined. A closed-spherical shell model proved to be a good indicator of the frequency response of a dry human skull in the frequency range of normal human hearing.