A subtle controlled ‘Stapedius Reflex’





externally activated spring-mass system Schematic drawing

The cooperative functioning of the eardrum and ossicular chain attenuation can be regarded as in this schematic drawing of the ear as an externally activated spring-mass system. Fig. 2.

Ossicular chain and eardrum function, together operating as a continuous sound reduction mechanism for changes in the strength of the offered signal. The tympanic membrane and the ossicular chain can be seen as a spring-mass system with amplification facilities, like it is shown in this figure.


The combined action of the ossicular chain and the eardrum is hypothesized to provide for both permanent volume control of the input sound and for overload protection. The stapedius reflex, evoked by sudden strong sound signal, cannot be seen as anything else than an extreme manifestation of the very mechanism that the schematic drawing of the ear as an externally activated spring-mass system propose.

by Willem Christiaan Heerens


“Based on our insights derived from literature we arrive at one more basic principle that form the cornerstones of our model: namely, the fact that the attenuation of the eardrum and the ossicular chain are at the root of the extremely large dynamic range of our auditory sense.”






“Analog to the diaphragm function of the iris.”