Cochlears for Kids:
A look at the technology and choice behind cochlear
implants for children
Abstract: Cochlear implants first appeared in the 1980s, and their three-decade journey is
filled with advances, new insights, and controversy. Cochlear implants are devices for those
with profound hearing loss. They convert sound waves into electrical impulses the brain
interprets as sound despite damaged portions of the inner ear. The surgery to implant the
device is simple but expensive; the most important and complex part of the process is
actually the post-surgery language training. The time it takes to associate sounds with
meanings leads to an emphasis on performing the implantation on children before age two.
Cochlear implants, therefore, are often the result of parental decisions, which creates a
bitter controversy between the Deaf World and those who advocate for the technology. Our
interview with a surgeon who performs the implant procedure and someone who grew up
with the implant provides insights into the decision process.
Laura Patch
Jaclyn Wallenmeyer,
Qinxin Luo
Farhad Mohammad Tehrani
CCT 506
Fundamentals of Technology
Profs. Ribes and Barba
T.A. Cassidy Smith
Cochlears for Kids 2
Introduction
Cochlears for Kids examines the technology and context behind pediatric cochlear
implants (CIs). These devices work by circumventing damaged areas of the natural hearing
system and permit individuals who are deaf to perceive sounds. They send electrical currents or
impulses to the brain, which interprets them as sound. Approved in 1985, improvements to the
technology since have increased oral communication. Once single-channel devices, the current
multi-channel models allow sound differentiation with regards to frequency and pitch. Experts
recommend CIs for young children so they can develop language at rates similar to naturalhearing individuals.
We researched CIs in three steps. In the first step we read guides written by health
institutions and manufacturers to learn how the device works and future improvements. Second,
we examined academic articles about the ethics of CIs and the controversies surrounding them.
Last, we conducted an interview with an expert and a user. We spoke with Dr. Mark Dettelbach,
a pediatric specialist, from the Feldman ENT Group. We also interviewed Ethan Young, who
received a CI at age 3, and he explained his experience with the device.
This paper examines how CIs work, post-surgery requirements, the controversies around
CIs, and areas for future development and research. First, we explain natural hearing, since CIs
act both within that system and circumvents it, and then we describe the technology of CIs and
its various components. Second, we discuss the post-operation care. Individuals must undergo
therapy to understand sounds. Third, this paper discusses the conflict between the Deaf World
and advocates of CIs. The Deaf community is very resistant to CIs because they treat hearing
loss as a “problem” that needs to be fixed and diminish the Deaf World culture. Last, we look at
future developments and areas for further research.
Cochlears for Kids 3
CIs: How do people hear?
CIs are electronic devices that allow deaf or severely hard-of-hearing individuals* to have
a sense of sound. This small device is a complex mixture of external portions and pieces that are
surgically place under the skin and in the ear canal. These implants work differently from
hearing aids in that instead of amplifying sound, they bypass damaged portions of ears to directly
stimulate the auditory nerve.1
Natural hearing is a system in which sound waves are converted into electrical impulses
the brain interprets,2 and it requires several parts of the ear. Sound waves travel down the ear
canal to strike the eardrum, which causes the eardrum to vibrate. Behind the eardrum are three
small bones called ossicles.3 These connect the eardrum to the inner ear, or cochlea. When the
eardrum vibrates, these bones begin to vibrate, creating movement of fluid in the cochlea. These
liquid waves cause the tiny hair cells inside the cochlea to move. The hair cells absorb the
movement and convert vibrations into electrical impulses, which are sent to the auditory cortex.
This portion of the brain interprets the impulses as sound.4
A CI circumvents this system by directly stimulating auditory nerves. The device has two
parts; an external system and an internal implant. The external system includes a microphone, a
sound processor, and a transmitter.5 The implant includes a receiver and an electrode system.6
The speech processor uses one or two small microphones to pick up sounds. The speech
processor and microphone are typically worn around the ear, similar to a typical hearing aid.7
Processors were originally small box units worn in jacket pockets, but the ability to make
computer chips smaller allows the speech processor to now be in the same unit as the
microphone and worn behind the ear.8 It turns sounds, which enter the microphone, into digital
*
An individual is considered deaf if the hearing loss is 80 db or more, and severely hard of hearing if the hearing
loss is in the range from 60-20db ("Understanding Severe-to-Profound Hearing Loss." Beltone. Beltone, 2013. Web.
19 Apr. 2013.)
Cochlears for Kids 4
signals and sends them to the transmitter, which then sends the signals through the skin to the
receiver. The receiver is a disk item surgically inserted behind the individual’s ear. During
surgery, the skin is opened and a portion of the skull is shaved, creating a well, not a hole in
which the disk lies flat once the skin is stitched closed. The receiver converts the signals into
electrical currents that travel along the electrode array. The electrode array is usually a wire,
which connects the receiver directly to the auditory nerve, by going through the cochlea and
bypassing the damaged hair cells.9 To place the electrode array, surgeons drill through the
mastoid bone encasing the cochlea.10 These electrical currents stimulate nerve fibers in the
cochlea and, as with natural hearing, the brain recognizes these signals as sound. When the
technology was first implemented, the malfunctions occurred with the electrode array as it could
dislodge.11 If the wire becomes unattached, signals no longer reach the nerve fibers, rendering
the entire system useless. They now use a longer wire, which practically eliminates this
problem.12
The most complicated portion of CIs is the external element. This outside portion, as
already mentioned, consists of the transmitter, microphone, and a speech processor. The
transmitter is basically a coil encased in plastic, with a magnet on one side (the side that faces
towards an individual’s head). The magnet keeps the transmitter in place as it attracts the metal
receiver. Attached to this transmitter is a wire connected to the behind-the-ear (BTE) component.
The BTE houses the speech processor, microphone, batteries, ear hook, and volume control. It
runs on rechargeable batteries the user can easily access by dissembling the piece. It also
includes a filter, which must be routinely cleaned or the transmitted sounds begin to distort with
static noise.13 On newer models, there may also be a digital display offering setting information.
A requirement of post surgery is selecting these settings, discussed later in this paper. For
Cochlears for Kids 5
children, experts freeze these settings so children cannot change their implants by accident and
alter how the devices convey sound between visits to their doctors. You can think of these locks
as childproof medicine caps that prevent children from accessing programming.
The speech processor and its programming are essential because they convert sound into
electrical impulses. The microphone sends sound in the form of electricity, and the processor
codes the electricity into signals the brain recognizes.14 It uses a process of analog-to-digitalconversion, similar to converting an old-fashion record into the digital music files we use on
iPods. Sound waves are continuous waves that alter based on the pitch or frequency. The sound
processor takes samples of the incoming waves and codes them based on pitch/frequency and
loudness. Since this conversion process requires compression, individuals who rely on CIs do not
receive the same data they would if hearing naturally. This method is why doctors say the
technology does not “cure” or “restore” hearing.15 CIs do not offer individuals a chance to have
super sonic hearing, or even hearing equal to natural hearing. The microphone especially has
difficulty picking up relevant sounds and filtering unnecessary noises in crowded places, which
natural hearing can. The speech processor, however, can communicate some differences in sound.
“Variations in the power and tempo of the electrical signals convey various sounds by triggering
different patterns of impulses in the hearing nerve.”16 Sound itself has two characteristics that
play a role in the conversion process, pitch/frequency and loudness.17 In current CIs, pitch or
frequency is conveyed through a channel system. Channels are simulation sites created in the
cochlea by the electrode array.18 The processor splits signals and sends them to different
channels based on pitch and frequency.19 The more channels a device has, the more likely the
signal created by a CI will resemble natural hearing. The processor communicates loudness
through strength, or size, in the transmitted signal.20
Cochlears for Kids 6
While CIs do not cure deafness, they do allow people to perceive sounds. They give
individuals information about the environment and help them understand speech.21 Individuals
with the device increase their ability to communicate with others. Most experts “agree that
cochlear implants do not restore completely normal sensory information, but they do provide
important cues for speech perception.”22 CIs, in many cases, make it easier to function in
mainstream society. However, a CI does not guarantee people the ability to hear and speak at
natural levels. The amount of perceptible sounds can change on a case-to-case basis.
A concern with this technology is that it requires surgery. The surgery, however, is
relatively low-risk. Dr. Dettelbach explained, “the surgeon actually has the smallest role in the
whole process of cochlear implantation.”23 The surgery is frequently performed on an outpatient
basis for adults. Doctors may keep children overnight to ensure their safety. A few patients may
experience dizziness afterwards as a result of the stimulation of their ear, but infection is very
rare.24 The total cost is very expensive. It can easily cost over $50,000. Recently insurance
companies began covering this cost, but not all do.25 There are many individuals who cannot
afford to get a CI, and the cost is a huge factor in why many do not receive bilateral CIs.†
Context: After implantation
Since CIs digitize sound, individuals must learn or relearn language. The difference
between natural sounds and sounds transmitted through a CI varies enough that sounds must be
re-associated with their meanings. The key to success with CIs is working with audiologists and
speech pathologists for extensive periods.26 After a healing period of 4-6 weeks, individuals are
fitted for the external portions, and hear using the device for the first time.27 Individuals will not
†
Bilateral cochlear implants are CIs in both ears. Studies show that bilateral implantation greatly increases an
individual’s ability to develop language. However, many insurance companies have strict requirements a patient
must meet before she/he receives approval for a second CI. These conditions include demonstrated benefits of the
first CI, meaning that most individuals cannot receive two CIs at the same time, which would cost less than two
separate surgeries.
Cochlears for Kids 7
be able to understand speech immediately, and thus therapy is required. At the time of activation,
audiologists and the recipient work together to adjust the speech processor’s programming. This
practice is called mapping and entails adjusting the volume levels and sensitivity of stimulation
spots.28 Basically, mapping is the method through which channels are set for optimized hearing,
or perception of sound. As an individual’s skills using the implant develop, the mapping needs
adjustment, so frequent check-ups are necessary at the beginning and can taper to annual ones
later.29 In addition to mapping, recipients require speech therapy to develop language. Adults can
receive CIs and regain language understanding, but the older an adult is, the harder it may be to
learn as brains are fully developed. Children relearning, or learning for the first time, how certain
sounds associate to different people and situations typically find the process easier than adults as
their brains still have elasticity.30 Thus, CIs are highly recommended for young children. In fact,
with the introduction of neonatal hearing screening in the 1990ss, implantation increased
dramatically.31
Furthermore, deafness at a young age dramatically effects a child’s development of
language. 1.2 to 1.7 children in every 1,000 live births are born with hearing loss, and 20-30% of
those have profound hearing loss.32 The number of children who are deaf “increases up to 6
years of age as a result of meningitis, the delayed onset of genetic hearing loss, or late diagnosis.”
Studies show that children who are deaf by age 3 fall significantly behind hearing children in
ability to master language, whether written, read, spoken, or signed forms, and this trend is
regardless of whether the child uses oral communication (excludes signs) or total
communication.33 By high school graduation, the median reading level of children who have
been deaf since a young age is below the level of natural-hearing third graders.34 CIs will not fix
this gap. Deaf children still learn language at slower rates than their natural-hearing peers
Cochlears for Kids 8
because there was a delay in their learning. However, when compared to children that do not
receive the implant, children with CIs acquire language skills at faster rates, with a mean rate
closer to that of natural-hearing children.35 If a child receives the technology after age 7, a more
noticeable gap in language acquisition will occur.36 However, if a child born with profound
hearing loss receives the implant before age two, she or he will enter first grade with receptive
and expressive language skills close to their natural-hearing peers.37
Context: Tensions between the Deaf and Hearing Worlds
The largest controversy about the technology does not concern the expensive surgery,
although that certainly is a barrier, but arises from tensions between those who want the implant
and the Deaf World.‡ “Perspectives on implants vary according to whether one adopts a
‘medical/disability’ or a ‘social/cultural’ model of deafness.”38 The Deaf World does not see
themselves as handicapped. They view the strong advocacy for CIs within medical and press
circles as belittling of their “linguistic and cultural values.”39 Advocates of the Deaf World
object to pediatric CIs on two levels. The first is that they believe CIs do not increase perception
skills by children enough to be worthwhile. As the technology offers sensory information, the
benefit to oral language can be small. The second is that it is unethical for parents make the
choice for children. The choice to receive pediatric CIs is often made by parents “who have not
before been familiar with deafness and the possible lives of deaf people.”40 Some in the Deaf
World see this choice essentially as “genocide,” resulting in dwindling numbers of children who
would be part of the Deaf World.41 When choosing to have their child receive an implant, parents
should consider that they are denying their child full entry to the Deaf World. It can place a child
in the awkward position of not belonging to either the hearing community or the deaf one.
‡
The Deaf World refers to a community comprised of members and advocates of a linguistic and cultural minority
in the United States that uses sign language as their primary language.
Cochlears for Kids 9
The Future
As technology around microelectronics advances, so do the possibilities for CIs. One of
the newest models of the external pieces is waterproof. Older models require individuals to
remove external portions during showers or swimming, leaving the individual completely deaf
during these activities.42 Cochlear Nucleus created a model on which a blue tooth device can
connect directly to the BTE element so individuals answer phones through their CI.43 Since
transmitting through skin is the most difficult portion of the process, manufacturers are working
on ways to reduce this weakness. One corporation just trademarked a device that anchors into
bone. It is basically a screw partially inside and partially outside the skull. The speech processor
would screw into it, eliminating the need to pass signals through skin.44 The problem with new
models is that they must work with old receivers.45 Since there are always inherent risks in
surgeries, it is impractical to change receivers every time people choose a new external model.
Companies, therefore, must consider the programming of old receivers when developing new
speech processors.
In addition to new developments in models, there further research is needed.
Acknowledged benefits of CIs result from the current sample of individuals with CIs. However,
in the US “there are substantial differences in rates of implantation among groups of children
who are potential implantees on the basis of race, presence of an additional disability, and
socioeconomic status (SES).”46 The rate of implantation for White and Asian American children
is five times higher than those of Hispanic or African American background.47 Since
implantation is costly, and insurance companies did not originally cover the surgery and therapy,
individuals who received them in the 1980s and 1990s tended to be from high-income families.
Cochlears for Kids 10
This discrepancy means that individuals may have access to better resources post surgery,
increasing the likelihood that language develops. Further research should focus on how efficient
CIs are in children who are unable to access these resources.
Components
Interviews: Our main interview was with Dr. Dettelbach from the Feldman Group of
ENT. Dr. Dettelbach performs the implantation surgeries. He was able to offer insights on the
surgery and the benefits to hearing. Additionally, we interviewed Ethan Young as a user of the
technology. Ethan, a college student, received a CI at age 3. He shared his experience of growing
up with one and the amount of care it takes for the device to work efficiently.
Survey: Many of our academic sources mention that parents make the choice to get a CI
for their child without fully understanding the device or knowing about the resources available in
the Deaf World. However, our research comes from the perspectives of doctors and other experts.
We, therefore, designed two surveys to gather information directly from parents. For more
information about our surveys, see the Appendix.
Poster: Our poster aims to explain the different components of the technology, introduce
the Deaf World controversy, and explain required steps post implantation. The poster provides
visuals to connect the portions of the device with their location and separate the external
elements from the internal ones. Consequently, our main image is that of a head, opened to the
inside so one can see the internal portions. The poster relies heavily on our color scheme to make
the poster child-friendly. While we mainly target parents, we also want children to feel interested.
Furthermore, we created a postcard and brochure to accompany the poster. The postcard is
mostly to define what the technology is, whereas the brochure offers succinct, but detailed
information about CIs, covering all aspects of our research.
Cochlears for Kids 11
Video: Our video offers a summary of the findings of our research. Using clips from our
interviews with Dr. Dettelbach and Ethan, we explain how the technology works and the process
that occurs afterwards. Dr. Dettelbach explains that the surgery is the simplest portion of
receiving a CI. The learning process afterwards requires more attention. Ethan discusses life with
an implant, including how to care for the external portion. The video offers visual depictions of
the technology so watchers can better understand the pieces.
Website: Our website conveys information both about the technology and the controversy.
We oriented the project to communicate information to parents with young children.
Additionally, we wanted the site to be friendly for young children that have CIs in case they want
to learn more about the technology. We include the academic information we learned, but use
language and visuals parents without much understanding of hearing or technology can
understand. We also added a “Kid’s Page” specifically for children.
Conclusion
Pediatric CIs do offer benefits for deaf children, but there are also downsides. Frequently,
parents make the choice for their child without having all of the information or fully
understanding the technology. Since doctors are strong advocates of the technology, hearing
parents of deaf children may not understand the other choices available to them. Additionally,
parents feel that their children can have their hearing fully restored, not realizing that CIs offer
limited perception of sound. It is important that information delivered to parents contain both
explanations of the technology, and the Deaf World options for their child.
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2 Dettelbach, Mark. "Dr. Dettelbach." Personal interview. 5 Apr. 2013.
3 "Auditory System." Wikipedia. Wikimedia Foundation, 15 Apr. 2013. Web. 19 Apr. 2013.
4 "The Ear: Auditory and Vestibular Systems." Partners in Assistive Technology Training and Services. N.p., July 2001. Web. 18 Mar. 2013.
Cochlears for Kids 12
5 "How Does a Cochlear Implant Work?" Cochlear Implant Online. Cochlear Implant Online, 2012. Web. 19 Mar. 2013.
6 "What Is a Cochlear Implant?" Medical Devices. FDA, 8 Sept. 2010. Web. 19 Mar. 2013.
7 "Cochlear Implants." ASHA.org. American Speech-Language-Hearing Association, 2013. Web. 19 Mar. 2013.
8 Wilson, Blake S. "Engineering Designs of Cochlear Implants." Cochlear Implants: Auditory Prostheses and Electric Hearing. New York:
Springer-Verlag, 2004. N. pag. Google Books. Google. Web. 19 Apr. 2013.
9 "Animation: Normal Ear, Ear with Hearing Loss, and COCHLEAR IMPLANT Procedure."Medical Devices. FDA, 23 Sept. 2011. Web. 19 Mar.
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10 "Inside a Cochlear Implant Surgery." Cochlear Implant Online. COCHLEAR IMPLANT Online, 8 Apr. 2008. Web. 19 Mar. 2013.
11 Dettelbach
12 Dettelbach
13 Young, Ethan. "Interview with a COCHLEAR IMPLANT recipent." Personal interview. 13 Apr. 2013.
14 "Speech Processing Strategies." BCIG.org. British COCHLEAR IMPLANT Group, n.d. Web. 21 Apr. 2013.
15 Asha
16 "Cochlear Implant Information." Johns Hopkins Medicine. The Johns Hopkins University, The Johns Hopkins Hospital, and Johns Hopkins
Health System, n.d. Web. 21 Apr. 2013.
17 Speech Processing Strategies
18 "Single Channel versus Multi-Channel Cochlear Implants." HealthyHearing.com. Healthy Hearing, n.d. Web. 21 Apr. 2013.
19 Speech Processing Strategies
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21 "COCHLEAR IMPLANTs." ASHA.org.
22 Svirsky, Mario A., Amy M. Robbins, Karen Iler Kirk, David B. Pisoni, and Richard T. Miyamoto. "Language Development in Profoundly
Deaf Children with Cochlear Implants." Psychological Science 11.2 (2000): 154.
23 Dettelbach
24 Dettelbach
25 Dettelbach
26 Dettelbach
27 COCHLEAR IMPLANT Information
28 COCHLEAR IMPLANT Information
29 ASHA
30 Sharma, Anu, Michael F. Dorman, and Anthony J. Spahr. "A Sensitive Period for the Development of the Central Auditory System in
Children with Cochlear Implants: Implications for Age of Implantation." Ear and Hearing 23.6 (2002): 532-39.
31 Hyde, Merv, and Des Power. "Some Ethical Dimensions of cochlear implantation for Deaf Children and Their Families." Journal of Deaf
Studies and Deaf EducationWinter 11.1 (2006): 102-111.
32 Kral, Andrej, and Gerard M. O'Donoghue. "Profound Deafness in Childhood." New England Journal of Medicine 363.15 (2010): 1438.
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34 Svirsky 153.
35 Svirsky 155.
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44 Hewitt, John. "Upgrade Your Ears: Elective Auditory Implants Give You Cyborg Hearing." ExtremeTech. Ziff Davis, Inc., n.d. Web. 21 Apr.
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45 Young
46 Hyde 103.
47 Hyde 103.