Jennifer Matthews: It can be a nuisance sometimes but noise like this is a welcome change for people like Marlene Hunter.

Marlene Hunter: When I was 5 years old, I developed the mumps and that caused nerve damage to my hearing.

Jennifer Matthews: Her hearing has progressively gotten worse.

Marlene Hunter: Missing out on a lot of hearing and doing things and going places in just my natural environment not knowing what was going on.

Jennifer Matthews: Doctor Moises Arriaga says hearing aids are far from perfect.

Moises Arriaga: They cause feedback. They cause an occlusion effect that makes it not sound very clean, and they really have a lot of problems with background sounds.

Jennifer Matthews: But times are changing. Doctor Arriaga is studying this implantable envoy hearing system.

Moises Arriaga: There is absolutely nothing externally seen or worn by the patient, so the device can be on all the time.

Jennifer Matthews: The device is implanted behind the ear. Sound is collected by crystals on a wire and processed through the battery. It's then sent as an electric signal to a wire attached to the ear bones.

Moises Arriaga: Patients are describing that the sound is more natural and clearer than they ever remember it.

Jennifer Matthews: Marlene used to read lips in the mirror to understand her clients. But she got the envoy last may, and it changed her life.

Marlene Hunter: I could be out in the world more and listening and talking to people, understanding them, and I could communicate much better.

Jennifer Matthews: with her hearing restored, Marlene keeps her eyes focused on the job at hand making her clients happier too. This is Jennifer Matthews reporting.