I pointed out that the mammalian middle ear ossicular chain is an IC system providing an impedance-matching function, and that the impedance-matching goes away if you remove any of the parts.    From Wordnik.com.  [2008 November - Telic Thoughts] Reference

According to the company, Esteem works by replicating the ossicular chain -- a group of three small bones known as the hammer, anvil, and stirrup -- which amplify sound vibrations that enter the middle ear.    From Wordnik.com.  [MedPageToday.com - medical news plus CME for physicians] Reference