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NIH MedlinePlus the Magazine, Trusted Health Information from the National Institutes of Health

Special Section:
Focus on Communication

Cochlear Implants

Mia, and Isabelle Jeppsen meet with Mia’s cochlear implant surgeon, John Niparko.

Twin sisters Mia, right, and Isabelle Jeppsen meet with Mia's cochlear implant surgeon, John Niparko, M.D., of Johns Hopkins University.
Photo: Johns Hopkins University

Keep Twin Sisters Learning, Discovering Together

Mia and Isabelle Jeppsen, 10, share brown eyes, broad smiles, and engaging personalities. Like most other twins, they experience practically everything together.

Except Mia is deaf, and Isabelle is not.

Had Mia been born before 1990, things might have been very different. Cochlear implants—small, sophisticated electronic devices—have been approved for children in the U.S. since 1990. Thanks to them, Mia is able to interpret sound, speak, read, and write. She is developing crucial language skills and keeping pace in school.

The girls were born prematurely in 1998 to Carolyn and David Jeppsen, who then lived in Tokyo. Neonatal testing confirmed that Mia was deaf, and she was fitted with hearing aids.

When they returned to the U.S., the Jeppsens began working with John Niparko, M.D., of Johns Hopkins University School of Medicine in Baltimore. With support from the National Institute on Deafness and Other Communication Disorders (NIDCD), he studies how the language skills of children with cochlear implants progress.

Tests showed that Mia could not discern different sounds well. Niparko and his team surgically implanted her first cochlear device at age 2 ½, her second in 2007. Having two implants helps Mia to identify the location of a sound and makes it easier to hear in noisy environments—a critical ability in a classroom.

Before the second implant, Mia was pulling back from group settings, because she couldn't process the jumble of sounds. Says her mother, gratefully, "There's the obvious benefit of learning to read, write and communicate with facility and it's made a real difference in social situations."

an illustration of a cochlear implant

A cochlear implant does not amplify sound. It is a surgically implanted electronic device that stimulates auditory nerves with electric impulses.
1. Microphone 2. Speech processor 3. Transmitter
4. Receiver/stimulator 5. Electrode array
Photo courtesy of NIH/NIDCD

While cochlear implants are appropriate for a limited number of those with severe hearing loss, NIDCD sponsors research to improve cochlear implants and other communication aids. These include:

  • hearing aids,
  • brain stem implants that facilitate hearing for people who cannot be helped by cochlear implants because of damage to the auditory nerve,
  • devices similar to cochlear implants but adapted to support balance, and,
  • communication aids for people with speech-language production disorders.

To Find Out More

For more information on cochlear implants, see

Fall 2008 Issue: Volume 3 Number 4 Page 14