Presented to Carleton University By Bob Baillargeon,Thursday November 11 th 2010 Cochlear Implant Technology

Did you know that… Hearing Loss is the 4th Most Prevalent Disability in Canada after Mobility, Pain and Agility. (Source: Statistics Canada, Participation and Activity Limitation Survey, 2001) ‏ 40% of Persons over the age of 65 Report a Significant Hearing Loss (Source: Statistics Canada (December 2002)) ‏ Today’s Youth are also at Risk of Significant Hearing Loss –At 85 dB, you can listen to music for 8 hours with no damage. But for every 3 dB increase, cut that time in half. 4 hours for 88 dB 2 hours for 91 dB (subway, lawnmower) ‏ ½ hour for 97 dB (motorcycle) ‏ 15 minutes at 100 dB (school dance) ‏ for a concert which can be 110 dB and above… less than a minute! (Source: Ontario Association of Speech-Language Pathologists and Audiologists (2005)) ‏

Who motivates the hearing impaired adult to seek help? Self30% Spouse25% Physician19% Children12% Friend10% Other4% Adam, 1999

Anatomy of the Ear Outer ear Middle ear Inner ear - cochlea Normal Inner EarDamaged Ear Inner Hair Cells Outer

Four primary styles of Hearing Aids Completely In the Canal (CIC) ‏ In The Canal (ITC) ‏ In The Ear (ITE) ‏ Behind The Ear (BTE) ‏

Completely in the Canal (CIC) ‏ Fits deeper in ear canal (custom made) ‏ Mild to moderate or sloping high-frequency hearing losses Not usually for children Advantage: –Smallest size (least visible) ‏ Disadvantages: –Small size can be difficult to handle –Small batteries are changed more often –Cannot be used with some accessories –Can be damaged by earwax & ear drainage

In The Canal (ITC) ‏ Fits in ear canal (custom made) ‏ Mild to moderately-severe hearing loss Not usually for children Advantage: –Smaller size (barely visible) ‏ Disadvantages: –Small size can be difficult to handle –Cannot be used with some accessories –Can be damaged by earwax & ear drainage

In The Ear (ITE) ‏ Fits completely in the outer ear (custom made). Mild to severe hearing loss Not usually for children Advantages: –Small size –Can be used with add-on accessories Disadvantages: –Small size can be difficult to handle –Can be damaged by earwax & ear drainage

Behind The Ear (BTE) ‏ Fits behind the ear with custom earmold or slim tube in outer ear Mild to profound hearing loss Can be used by all ages Advantages: –Durable –Larger size easier to handle & maintain –Separate earmold can be easily replaced –Easy to use with assistive listening devices Disadvantage: –Larger size (highly visible) ‏

What all hearing aids have in common? A battery A microphone An amplifier Loudspeaker

Cost of hearing aids Some coverage offered: ADP(Assistive Device Program) in Ontario = $500/3 years/ear. Patient still has to pay between $600 to $2500 per ear after ADP contribution. The cost is the same for adults and children

Facts about Hearing Aids Hearing aids do not completely correct a hearing loss 100% Hearing aids amplify all sounds Hearing aids will help hearing in many situations Benefits of hearing aids depend on several factors Two hearing aids are better than one Adjusting to hearing aid(s) is a long process

Some simple communication strategies: Face the hearing impaired person so lipreading is possible Speak more slowly and distinctly, do not shout! Rephrase instead of repeating Write down a few key-words if necessary

Other possible options Bone Anchored Hearing Aid Titanium fixture/external abutment/sound processor Typically for congenital atresia or chronic ear infections Implantable Hearing Aid –Alternative to an acoustic hearing aid, for mild to severe sensorineural hearing loss Cochlear Implant BAHA Vibrant Soundbridge

What is a Cochlear Implant ? Surgically implanted device. Electrode Array and a Receiver-Stimulator But it works only if used with: External components: Speech Processor, Headpiece & Battery To work, it needs : Programming with a computer To work even more optimally: Rehabilitation sessions necessary

External components: Speech Processor, Headpiece & Battery

What does it look like? Illustration from Advanced Bionics

When to refer an Adult for a CI? Bilateral severe to profound sensorineural hearing loss Limited benefit from appropriate hearing aids i.e. poor speech recognition Telephone use is difficult, limited or impossible Patient relies heavily on speech reading or note writing to understand speech Patient is distressed by the inability to communicate efficiently on a daily basis No medical contraindications

Children Candidacy Severe to profound sensorineural hearing loss in both ears Lack of benefit from hearing aids and therapy No medical contraindications High motivation and appropriate expectations for child and family Placement in educational program that emphasizes auditory skills 12 months and up; may be indicated earlier for special cases

Other considerations Age Duration of deafness Language Mode of Communication Other handicaps Motivation

How is a Cochlear Implant Different from a Hearing Aid? Hearing Aids: –acoustically amplify sound –rely on the responsiveness of surviving hair cells Cochlear Implants: –bypass damaged hair cells Convert the acoustic input signal into electrical impulses to stimulate the auditory nerve fibers in the cochlea. The resulting electrical sound information is sent through the auditory system to the brain for interpretation.

How does it work? Sound Processor captures sound from the environment processes sound into digital information transmits to the implant. 2. Implant converts transmitted information into electrical signals delivers signals to the electrodes for stimulating the hearing nerve. 3. Hearing Nerve carries the sound information to the brain, where it is interpreted.

Evaluation Process Audiological Medical Psychological & Social Worker (children) ‏ Auditory-Verbal Therapy (children) ‏ Speech Language Pathology (for adults, when required) ‏

Audiological Assessment Diagnostic testing: –Audiogram –Tympanometry & Acoustic Reflexes –Auditory Brainstem Response –Otoacoustic Emissions Speech perception tests with appropriate amplification Counseling re: types of implants & expectations

Medical Assessment Otologic history & examination General medical health Pneumococcal meningitis vaccine: Pneumovax Diagnostic Imaging Computed Tomography (CAT) Magnetic Resonance Imaging(MRI)* Electronystagmography ENG (Adult only) ‏ Electronystagmography (ENG) is a diagnostic test to record involuntary movements of the eye caused by a condition known as nystagmus. It can also be used to diagnose the cause of vertigo, dizziness or balance dysfunction by testing the vestibular system.

Surgery Risks and/ or Adverse Effects Facial nerve injury (less than 1/300 to 1/500) ‏ Small possibility of infection The small amount of hearing in the operated ear will be lost. Some discomfort or numbness around the implanted ear after the surgery Temporary dizziness, tinnitus or taste disturbance MRI precautions after surgery

Surgery Inpatient procedure Requires general anesthesia Duration ~ 3-4 hours

Behind-The-Ear/Device Marking Template The Behind-the-Ear/Device Marking Template is used to allow adequate clearance between the pinna, the speech processor and the headpiece. From Advanced Bionics

Device Coil Gauge After placing the Device Coil Gauge, an outline is drawn around the template. From Advanced Bionics

Incision Line Note: The surgeon will determine the length of the incision line. A conventional postauricular- scalp incision approximately cm in length for children may be used. The incision may be longer in adults if the scalp needs to be thinned. From Advanced Bionics

Recess Marking Template The Recess Marking Template is used to determine the location of the recess bed and channel for the electrode lead. From Advanced Bionics

Mastoidectomy-Facial Recess Approach After completion of a mastoidectomy-facial recess approach, the implant-receiver well/recess bed and electrode lead channel are drilled. Suture tie-down holes to stabilize the implant are placed. A standard cochleostomy is used. From Advanced Bionics

Electrode Insertion The insertion tool is used to insert the electrode array in the usual fashion. The Insertion Tube is placed just inside the cochlea toward the basal turn of the scala tympani, with the insertion tube slot directed toward the modiolar (or inner) wall. From Advanced Bionics

Closure The skin incision is closed in layers. From Advanced Bionics

Electrode Array Placement Within the Cochlea Illustration courtesy of Cochlear Corporation

Audiological testing in the OR Impedance check on all electrodes Neural response testing to help estimate required levels

X-Ray to confirm position of internal device Courtesy of Cochlear Corporation

After the surgery Initial stimulation: 4-6 weeks post surgery Adjustments made regularly based on feedback from patients, parents, therapists and educators Rehabilitation to meet specific patient needs Regular follow-up appointments

Positive psychological & social benefits Decline in: -Loneliness -Depression -Social isolation Increase in: –Self-esteem –Independence –Social integration –Vocational prospect

Negative psychological & social impacts Concerns about the maintenance and/or malfunctioning of the Cochlear Implant Difficulty in background noise Unreasonable expectations of aural-only benefit on the part of the implant user or their family and friends

Potential Benefits 1.Better speech understanding compared to a hearing aid 2.Awareness and responsiveness to environmental sounds 3.Less dependence on family members for day to day living 4.Reconnection with the world of sound 5.Facilitation of communication with family and loved ones 6.Ability to talk on the phone 7.Better appreciation of music

Advanced Bionics Westinghouse Place Valencia, CA 91355