That could soon change, however, thanks to an experimental new implantable microphone.

Cochlear implants are used to address what's known as sensorineural hearing loss, which occurs when nerve endings within the inner ear's cochlea cavity have been damaged. An implant bypasses those dysfunctional nerve endings, directly stimulating the undamaged cochlear nerve itself.

With a typical cochlear implant, the external components include a microphone, a speech processor that enhances voices in the audio picked up by that microphone, and a transmitting coil that rests against the skin. The implanted components consist of a receiver that picks up the audio signal from the transmitter, a stimulator that converts that signal into electrical impulses, and electrodes that use those impulses to stimulate the cochlear nerve.

Because the external components are somewhat fragile and obtrusive, users have to take them off when swimming, sleeping, or engaging in rough-and-tumble activities such as sports. Additionally, some people find the appearance of the components off-putting, to the point that they may actually forgo getting an implant.

That's where the new "UmboMic" microphone comes in, as it would eliminate the need for any external components. Incorporating technology developed in a previous study, the prototype device was created by scientists from MIT, Columbia University, Harvard Medical School, and the Harvard-affiliated Massachusetts Eye and Ear hospital.

The fully flexible implant is about the length of a grain of rice, measures just 200 micrometers thick, and is made of a printed circuit board sandwiched between two layers of a biocompatible piezoelectric material called polyvinylidene difluoride (PVDF). Piezoelectric materials produce an electrical charge in response to applied mechanical stress.