Copyright, 1996 © Dale Carnegie & Associates, Inc.

Why Should I Wear A Hearing Aid If I Already Use A Cochlear

Implant?

Jodi Haberstock M. Sc., CCC-Audiology

Why Should I Wear a Hearing Aid on My Non-implanted Ear?1. Preserve the Non-implanted Ear

2. Better Hearing in Noise

3. Localization

Preserve the Non-Implanted Ear

Hearing aids keep the nerve cells in the ear stimulated.

By not wearing a hearing aid the ear does not get stimulated, which may cause the ear to lose its ability to process sound.

Better Hearing in Noise

Research (Ching) shows that when you can hear with both ears you can hear better in noise.

Localization

When you receive sound form both ears you can localize where that sound is coming from.

But Won’t The Two Different Types of Sounds Be Confusing? The hearing aid is an acoustical sound and

the cochlear implant is an electrical sound. However, research (Ching) indicated that

our brains are able to combine the two different types of stimulation and process it.

However, you will need to do adjustments sometimes.

Can a Child go back to Wearing a HA if they have Stopped? Research (Ching) shows that by gradually

reintroducing a hearing aid most children will adapt to the hearing aid again.

Ching’s Study

A group of 7 cochlear implant children who had not worn a HA for at least 3 years were gradually reintroduced to HA’s

One month later the children were tested. The first test had speech and babble noise

coming from different speakers.

Ching Study Continued

The speech signal was pointed at the hearing aid side.

The Children were asked to repeat both sentences and consonants presented at a signal-to-noise ratio (S/N ratio) of 10 dB and 15 dB.

Results:

The children could understand the sentences better and recognize consonants better when they wore a HA with a CI compared to a CI alone.

The improvement was greater at 10 dB S/N ratio than at 15 dB S/N ratio which revealed that when there is more noise the hearing aid benefit is more pronounced.

What About Localization?

In the same study, a pulsed noise was presented from 5 loudspeakers separated by 30 degrees in front of the child.

Results:

The children made less localization errors when they wore both a HA and a CI.

What Did the Parents Have to Say ?“He/She could recognize voices of familiar

persons and family members.”

“He was able to pick up and join the conversation that was out of context.”

“…was able to discriminate between different dog barks.”

What did the Teachers have to say?

“ …was more alert and attentive in class.”

“…participated better in group discussions in class because he could turn to the talker immediately.”

What about Adults?

The same researchers (Ching) did the study with adults.

For the binaural test when noise and speech were presented from different speakers with 15 dB S/N ratio, the sentence scores improved from 38% (CI only) to 50% (CI + HA).

What about Localization?

The study used 10 loudspeakers. Reduction of errors went from 39 (CI) to

32 (CI+HA).

What did the Adults Have to Say?“I could appreciate music better.”

“I could identify the talker in a group better and easier.”

“I felt more confident in classes and meeting.”

“I liked the quality of my own voice.”

“The other peoples’ voices sounded more natural.”

What about Interference?

None reported instances of inference or confusion.

Wow!….Why doesn’t Everyone wear both?

Factors Influencing HA Use with Cochlear Implants1. Duration of use Prior to Implantation

2. Residual Hearing

3. Cosmetic

4. Cost

Duration of Use prior to Implantation Sometimes it has just been too long. The person is unable to get used to the

sound of the hearing aid or hearing aid itself.

Residual Hearing

There could be little or no hair cells available to amplify for a hearing aid.

Cosmetic

Earmold. Too Bulky. Can not physically wear a hearing aid.

Cost

Can not afford a hearing aid Repairs, molds, batteries, etc.

What Kind of HA should I Use?

The type does not matter as much as the flexibility of the hearing aid.

You will need a strong Behind-The-Ear (BTE) style.

You need something that can be adjusted to help “match” the CI.

Options That I Like - Personal Opinion

Classic Analog High Power HAs Least Expensive. Might already own them.

Sometimes hard to match. No Feedback Manager.

Examples:

Phonak Super Front, Unitron US 80

Personal Opinion Continued

Programmable HAs Have Feedback Manager. Inexpensive. Can Program to match the CI

Examples:

Oticon Sumo XP and Sumo E

Phonak Novo Forte and Sono Forte

Programmable HAs

Oticon Sumo E Programmable BTE

Personal Opinion Continued

High Power Digital HAs Very Flexible Have Feedback Manager Easy to Match with CI

Must be High Power Digital Can Vary in Price

Examples of High Power Digitals

Phonak Supero (various models)

Widex C18

Personal Opinion Continued

Transpositional Hearing Aids Provides High Frequency emphasis. Has feedback manger. Adjustable.

Expensive. No Canadian Manufacturer. Can be hard to get used to the sound.

Transpositional Examples

AVR Sonovation’s

DSR model & Impact XP model

References

Ching, T., Psarros, C., Hill, M., Dillon, H., Incerti, P. (2001). Should children who use cochlear implants wear hearing aids in the opposite ear? Ear and Hearing, 22, 365-380.

Ching, T., Psarros, C., Incerti, P., Hill, M. (2002). Management of children using cochlear implants and hearing aids. Volta Review, 103 (1), 39-57.

Websites

National Acoustic Laboratories website @ www.nal.gov.au

Cochlear website @ www.cochlear.com

Jodi Haberstock M.Sc., CCC-A

Phone: 306-655-4170

Email: jodi.haberstock@saskatoonhealthregion.ca

Questions?