Introduction to Cochlear Implants for EI Service Providers

Roxanne J. Aaron, MA, CCC-A, FAAAThe Moog Center for Deaf Education

March 2005

Introduction

Hearing Loss Identified at Birth

Hearing Aids Fitted by age 3 to 6 months

Infants with Profound Hearing Loss Can Receive Cochlear Implants by age 12 months

Increased Caseloads of Young Children with CI

What is a Cochlear Implant?

A surgically implanted medical device that bypasses the damaged part of the inner ear to electrically stimulate the remaining neural fibers of the auditory nerve

Electrical current stimulates the remaining auditory nerve fibers in the damaged inner ear to generate sensations of hearing

What are the potential benefits of CI?

Access to sound Environmental sounds Speech sounds High frequency sounds Soft sounds

Development of speech recognition and speech communication

Who Can Get a Cochlear Implant?

Adults and children with severe to profound sensorineural hearing loss

Est. >90,000 recipients worldwide

Pediatric Candidacy Criteria 12 months old or older

Profound Sensorineural Hearing Loss; (Severe to Profound Sensorineural Hearing Loss if > 2 years old for Cochlear device)

Limited benefit from hearing aids

Open-Set Speech Perception (e.g.. MLNT; LNT) <20% Advanced Bionics and MED-EL, <30% Cochlear

Pediatric Candidacy Criteria No medical contraindications

No active middle ear disease No cochlear nerve or auditory pathway lesions Cochlear anatomy allows implantation

Able to tolerate surgery

Enrolled in an educational program that supports listening and speaking for communication

Highly motivated with appropriate expectations (family and child)

A Team Decision

ENT Specialist CI Surgeon Audiologist Speech/Language

Pathologist Educator of the

Hearing Impaired Child Psychologist Social Worker Parents

The Process of Obtaining a Cochlear Implant1. Hearing loss identification/diagnosis

2. Hearing aid trial (3-6 months)

3. Audiologic candidacy evaluation

4. Medical candidacy evaluation

5. Other evaluations (speech-language, educational, psychological, etc.)

The Process of Obtaining a Cochlear Implant

6. Team meeting

7. Surgery

8. Initial stimulation (a few weeks after surgery)

9. Ongoing CI programming (1 week, 1 month, 2 months, etc.)

10.Verification of performance with CI

The Process of Obtaining a Cochlear Implant

CI Surgery A 2 to 4 hour procedure completed under

general anesthesia The internal device is placed under the skin

behind the ear into a well created in the mastoid bone

The electrode array is inserted into the cochlea

Cochlear Implant Components

Internal Device Surgically implanted under

the skin Electronics package

(receiver-stimulator) with magnet

Electrode array placed inside the cochlea

External Device Worn on the body or at ear

level Sound/speech processor Microphone Coil with magnet

Cochlear Implant Components

The external components of the CI system pick up sounds, analyze them, and convert them into an electrical signal that is sent to the internal device located under the skin

Internal and external components are held close

to each other by a pair of magnets and communicate via transcutaneous transmission of a radio-frequency signal

Cochlear Implant Components

The internal device decodes the signal and sends electrical current to each electrode

When the electrodes stimulate the nerve fibers of the auditory nerve, the signal is received by the brain and interpreted as sound

Cochlear Implant Components

Cochlear Implant Companies

Devices from 3 manufacturers are FDA approved for implantation in children

Each company has their own internal and external components that are only compatible with each other Advanced Bionics Cochlear MED-EL

Advanced Bionics (www.cochlearimplant.com)

Clarion and Bionic Ear HiRes 90K internal

Platinum Series Processor

Auria BTE Processor

Cochlear (www.cochlear.com)

Nucleus Contour and Contour

Advance internals

SPrint processor

ESPrit 3G BTE Processor

MED-EL (www.medel.com)

Combi 40+ internal

Tempo+ BTE processor with 5 modular options

CIS-PRO+ body processor

Common Features of CI Sound Processors

Power Switch On-Off

Battery Charge Meter

Display Lights

Program Control Selects Program or MAP loaded into the processor

Individual programs may have differing parameters such as speech encoder strategy, rate of stimulation, pulse width

Individual programs have different electrical dynamic ranges for each electrode which affect the perception of soft, average, and loud sounds

Common Features of CI Sound Processors

Volume Control Adjusts level of loud

sounds within a program

Sensitivity Control Determines if distant or

very soft sounds will be processed

Know the Child and the Device

Know which CI the child is using

Know which settings have been recommended for the external processor Observe current settings Change to the recommended settings if needed

Verify the system is working prior to therapy Are the appropriate lights or displays working? Does child look up or alert to sound? Does child localize to sound? Can the child participate in a Ling or word sound check? Use monitor earphones

Know the Child and the Device

Talk to the CI audiologist about child's status, the device, and the recommended settings

Talk to parents about the child and the device Does the child use the device during all waking hours? Are the parents comfortable with maintaining and

troubleshooting the device?

Request support materials from the CI company (Educator Guides, Teacher Guides, Troubleshooting Guides, Videos)

Advanced Bionics 1-800-678-2575 Cochlear (Customer Service) 1-877-883-3101 MED-EL 1-888-633-3524

CI Programming Basics Audiologists select the parameters

for each listening program Speech encoder strategy Stimulation rate Number of electrodes stimulated, etc.

Audiologists work with each child to set the program(s) within the CI sound processor

CI Programming Basics The child participates in tasks to help

set the minimum and maximum amount of electrical current required for each electrode Threshold assessment

Behavioral observation Conditioned response (VRA, CPA)

Loudness scaling/balancing Electrophysiological measures (NRT, NRI,

ESRT)

CI Programming Basics

The settings derived during the CI programming session form a listening program or MAP that is loaded into the sound processor

The listening program or MAP contains information about the amount of electrical current required by the child for hearing

CI programming is an ongoing process designed to satisfy the child’s need for electrical stimulation to optimize the perception of speech

EI Therapists and CI Programming

EI therapists can assist the audiologist in CI programming directly or indirectly Due to more frequent contact, the therapist

may know the child better What toys does the child like or dislike? What motivates the child? Under what conditions does the child work best? How does the child behave when tired or bored with

a task?

EI Therapists and CI Programming Offer to directly assist the audiologist in CI

programming May be billable as “consultation with others” if

preauthorized

Offer to work on tasks in therapy that will facilitate CI programming Auditory detection tasks Concepts such as “big” vs. “little” to assist with

loudness scaling

EI Therapists and CI Programming Give feedback to the audiologist about

how the child is responding to sound during therapy What sounds can child detect? Are any sounds uncomfortable?

Keep the audiologist informed about the child’s progress in learning to communicate

Acknowledgements

Special thanks to the cochlear implant manufacturers for the images and support materials used for this presentation

Advanced BionicsCochlearMED-EL

Thank You