According to lead researcher, Roozbeh Ghaffari, the discovery could eventually lead to improved systems for restoring hearing.
Ghaffari and colleagues found that the tectorial membrane, a gelatinous structure inside the cochlea of the ear, is much more important to hearing than previously thought.
He said that the cochlea, a part of the inner ear where physical sound is translated into electrical signals for the brain.
Inside this coiled tube, sound waves glide along a thin membrane, known as the basilar membrane, causing hair-like fibers on the membrane to vibrate at different frequencies. Once stimulated, the fibers emit electrical pulses that the brain uses to determine the pitch of the sound.
The scientists discovered that hovering right above all of this is the tectorial membrane, along which a different kind of sound wave travels.
This wave, which bounces from side to side, can stimulate the hair cells and also enhance their sensitivity, which Ghaffari said might help elucidate how we can pick up on sounds that are as quiet as a whisper.
Ghaffari said that the findings have major implications for our understanding of how hearing works and potentially for hearing devices currently on the market.
"Most hearing aids we have now are terrible in that they just amplify and blast everything," Live Science quoted him, as saying.
"Our ears are smarter than that and know tricks that help us distinguish sounds. Having a better model for cochlear mechanics can lead to improved hearing aids and cochlear implants," he added.
The research is described in the advance online issue of the Proceedings of the National Academy of Sciences the week of October 8.