To better understand the mechanics of the middle ear in the chinchilla, we developed circuit models of the middle ear that are able to capture well the forward (from ear canal to cochlea) and reverse (from the cochlea to the ear canal) transmission of sounds by the middle ear. To determine the model parameters using previously reported measurements of the two-port parameters of the chinchilla middle ear, we developed a manual fitting procedure. The model was then used to gives us key insights into the mechanics of the chinchilla middle ear compared to other mammalian species: we found that the ossicular chains of chinchillas, cats, and guinea pigs are less flexible than in humans.
We re currently developing finite element models of the eardrum and ossicular chain of the mammalian middle ear.
1. Lemons, C., Meaud, J., 2016, Middle-ear function in the chinchilla: circuit models and comparison with other mammalian species, Journal of the Acoustical Society of America, 140(4):2375-2753