This is the "normal" auditory process by which pressure
waves are perceived as sound when the waves are passed through the
outer, middle and inner ear, eventually stimulating the auditory
Action Potentials of the Auditory Nerve
Action potentials are the electrical responses of the
auditory nerve. This is typically measured by the
Appropriate Expectations Post-implantation
There is a common assumption that cochlear implants allow
people to "hear normally." This is not the case and should not be
expected. It is appropriate to expect to have some degree, however
great or small, of adjustment to a cochlear implant. This
adjustment period may last from a few months to a year or beyond.
Adjusting to listening with a cochlear implant can be just as
difficult if not more so than adjusting to hearing aids.
Auditory Steady State Evoked Potentials
These auditory evoked potentials or measured electrical
responses of the nervous system are derived from the use of a
continuous or prolonged auditory (sound) stimulus by way of
Cochlear implants placed in both ears.
Cochlear Implantation Follow-up Appointments
Post-implantation cochlear implant follow-up appointments
are necessary to ensure that the device is working properly and
set to most closely fit the hearing needs of the recipient.
Follow-up appointments vary from individual to individual and may
require weekly, monthly, or yearly appointments.
The manner in which an acoustic sound pattern is picked
up and translated into an electrical signal.
Conductive Hearing Loss
A hearing loss due to damage in the middle or outer ear.
Deafness present at birth.
The method by which the auditory nerve is stimulated when
utilizing a cochlear implant.
The portion of the cochlear implant which is surgically
placed in the cochlea. The array contains individual electrode
contacts which provide electrical stimulation.
Electrically Evoked Compound Action Potential (ECAP) and
Physiologic Measures to Program the Speech Processor
The ECAP is an electrophysiological measure of the
auditory nerve response to the electrical stimulation provided by
a cochlear implant. With current cochlear implant technology, it
is possible to record these electrophysiological measures with the
electrodes of the cochlear implant. No surface electrodes need to
be placed on the skin. Additionally, no response is needed from
the listener. The measurements are objective and do not rely on
participant report. ECAP responses can only be measured when
stimulation from the cochlear implant is audible to the user.
Consequently, these measures can be combined with subjective
measures of loudness to aid in programming the speech processor.
The measurement of neural activity in response to a
stimulus. Neural activity can be measured by electrodes placed on
the skin, and can then in turn be displayed on a computer screen
and/or plotted on paper. Auditory Evoked Potentials (AEP) are a
commonly utilized electrophysiological measure used to estimate
hearing sensitivity. The most common AEP measurements used at our
center are the Auditory Brainstem Response (ABR) and the Auditory
Steady State Response (ASSR). They are often used in determining
cochlear implant candidacy. Additionally, the Electrically Evoked
Compound Action Potential (ECAP) is an electrically evoked
response that is often measured from cochlear implant users. It
measures the function and integrity of the auditory nerve.
Electrophysiological measures are non-invasive and are
almost always measured from outside the body with electrodes on
the surface of the skin. Typically, the electrodes look like small
stickers attached to wires which are then attached to a machine.
Greatest Benefit Derived from a Cochlear Implant
The desired outcome of the cochlear implant in terms of
its greatest benefit is to positively enhance the user's life more
so than would be possible without the device. There is not one
identical outcome for all users of cochlear implants. Each
recipient experiences their own individual triumphs and setbacks.
Working on a skill that has not yet been developed, such
as working on speech with a prelingually deafened child.
One method of providing information to the auditory nerve
via a cochlear implant. Fast stimulation rates theoretically
provide a more detailed signal to the hearing nerve by attempting
to preserve temporal or timing cues.
A system of symbols in the brain representing objects,
actions, and feelings that can be recalled and used to communicate.
Multi-channel Cochlear Implant System
A multi-channel cochlear implant system utilizes several
electrode contacts, which are laid out along the cochlea to
stimulate different frequency regions. Multi-channel systems
provide frequency as well as timing and loudness information.
Mixed Hearing Loss
A hearing loss due to damage in both the middle or outer
ear and the inner ear or auditory nerve.
Deafness that occurs after speech and language have been
learned and established.
Deafness that occurs prior to the development of speech
Working on an impaired skill that has already been
developed, such as working on speech with an adult that has
developed a hearing impairment later in life.
A detailed plan of a scientific or medical experiment,
treatment, or procedure.
The amount of hearing that an individual is able to
utilize, even in the presence of a hearing loss. Typically,
residual acoustic hearing is lost following implantation.
Sensorineural Hearing Loss
A hearing loss due to damage either within the inner ear
or the auditory nerve.
Severity of Hearing Loss
Severity of a hearing loss is determined by the air
conduction thresholds obtained by an audiologist during a hearing
test. Ask your audiologist the severity of your hearing loss based
on your most recent audiogram.
Normal hearing = 15 dB HL or above
Slight hearing loss = 16-25 dB HL
Mild hearing loss = 26-40 dB HL
Moderate hearing loss = 41 and 55 dB HL
Moderate-to-severe hearing loss = 56-71 dB HL
Severe hearing loss = 71 and 90 dB HL
Profound hearing loss = greater than 90 dB HL
Short Electrode Array
This device is often referred to as a Hybrid Cochlear
Implant or Electrical Acoustical Stimulation (EAS). It was
designed for use with patients who have a significant amount of
low frequency residual hearing. It consists of a short electrode
array that is implanted only in the basal end of the cochlea. The
external equipment used with this device combines electronics to
control both a cochlear implant and a hearing aid, allowing
patients to make use of residual hearing.
A set of rules that define how the speech analyzes
acoustic signals and codes them for delivery to the cochlear
Signal Processing Parameters
A set of guidelines for processing input and translating
it into electrical signals emitted by the cochlear implant. Signal
processing is carried out by the external speech processor. The
possible parameters are limited by the processing limits of and
power supply to the cochlear implant. Signal processing is often
referred to as a coding strategy.
Single Channel Cochlear Implant System
A single channel cochlear implant system utilizes an
electrode array with only one electrode contact. This single
channel allows for timing and loudness cues, but does not provide
frequency information. Most modern implants are multi-channel
Sound can be described as a type of vibration that
travels through the air in the form of a wave of pressure. Not all
sounds are speech.
Speech can be classified as orally produced sound waves
shaped by the vocal tract (oral cavity, nasal cavity, pharynx,
larynx, and the respiratory system) that a listener of that
language can derive meaning from. All speech is sound.
Ability to produce speech.
Speech Recognition or Perception Testing
Speech recognition or perception testing is one way to
determine the benefit obtained by a cochlear implant. When testing
for speech recognition, cochlear implant recipients are typically
required to repeat speech stimuli (i.e., consonants, vowels,
words, or sentences, etc.), either with or without the aid of visual
cues and either with or without background noise to determine the
percent that can be correctly understood with the use of the
cochlear implant. These scores are often compared to scores
obtained prior to implantation when individuals were wearing