Cochlear Implants Glossary

Acoustic Stimulation
This is the "normal" auditory process by which pressurewaves are perceived as sound when the waves are passed through theouter, middle and inner ear, eventually stimulating the auditorynerve.
Action Potentials of the Auditory Nerve
Action potentials are the electrical responses of theauditory nerve. This is typically measured by theelectrophysiology team.
Appropriate Expectations Post-implantation
There is a common assumption that cochlear implants allowpeople to "hear normally." This is not the case and should not beexpected. It is appropriate to expect to have some degree, howevergreat or small, of adjustment to a cochlear implant. Thisadjustment period may last from a few months to a year or beyond.Adjusting to listening with a cochlear implant can be just asdifficult if not more so than adjusting to hearing aids.
Auditory Steady State Evoked Potentials
These auditory evoked potentials or measured electricalresponses of the nervous system are derived from the use of acontinuous or prolonged auditory (sound) stimulus by way ofelectrodes.
Bilateral Implantation
Cochlear implants placed in both ears.
Cochlear Implantation Follow-up Appointments
Post-implantation cochlear implant follow-up appointmentsare necessary to ensure that the device is working properly andset to most closely fit the hearing needs of the recipient.Follow-up appointments vary from individual to individual and mayrequire weekly, monthly, or yearly appointments.
Coding Strategies
The manner in which an acoustic sound pattern is pickedup and translated into an electrical signal.
Conductive Hearing Loss
A hearing loss due to damage in the middle or outer ear.
Congenitally Deafened
Deafness present at birth.
Electric Stimulation
The method by which the auditory nerve is stimulated whenutilizing a cochlear implant.
Electrode Array
The portion of the cochlear implant which is surgicallyplaced in the cochlea. The array contains individual electrodecontacts 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 theauditory nerve response to the electrical stimulation provided bya cochlear implant. With current cochlear implant technology, itis possible to record these electrophysiological measures with theelectrodes of the cochlear implant. No surface electrodes need tobe placed on the skin. Additionally, no response is needed fromthe listener. The measurements are objective and do not rely onparticipant report. ECAP responses can only be measured whenstimulation from the cochlear implant is audible to the user.Consequently, these measures can be combined with subjectivemeasures of loudness to aid in programming the speech processor.
Electrophysiology
The measurement of neural activity in response to astimulus. Neural activity can be measured by electrodes placed onthe skin, and can then in turn be displayed on a computer screenand/or plotted on paper. Auditory Evoked Potentials (AEP) are acommonly utilized electrophysiological measure used to estimatehearing sensitivity. The most common AEP measurements used at ourcenter are the Auditory Brainstem Response (ABR) and the AuditorySteady State Response (ASSR). They are often used in determiningcochlear implant candidacy. Additionally, the Electrically EvokedCompound Action Potential (ECAP) is an electrically evokedresponse that is often measured from cochlear implant users. Itmeasures the function and integrity of the auditory nerve.
Electrophysiological Techniques
Electrophysiological measures are non-invasive and arealmost always measured from outside the body with electrodes onthe surface of the skin. Typically, the electrodes look like smallstickers 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 ofits greatest benefit is to positively enhance the user's life moreso than would be possible without the device. There is not oneidentical outcome for all users of cochlear implants. Eachrecipient experiences their own individual triumphs and setbacks.
Habilitation
Working on a skill that has not yet been developed, suchas working on speech with a prelingually deafened child.
High-Rate Stimulation
One method of providing information to the auditory nervevia a cochlear implant. Fast stimulation rates theoreticallyprovide a more detailed signal to the hearing nerve by attemptingto preserve temporal or timing cues.
Language
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 severalelectrode contacts, which are laid out along the cochlea tostimulate different frequency regions. Multi-channel systemsprovide frequency as well as timing and loudness information.
Mixed Hearing Loss
A hearing loss due to damage in both the middle or outerear and the inner ear or auditory nerve.
Postlingually Deafened
Deafness that occurs after speech and language have beenlearned and established.
Prelingually Deafened
Deafness that occurs prior to the development of speechand language.
Rehabilitation
Working on an impaired skill that has already beendeveloped, such as working on speech with an adult that hasdeveloped a hearing impairment later in life.
Research Protocols
A detailed plan of a scientific or medical experiment,treatment, or procedure.
Residual Hearing
The amount of hearing that an individual is able toutilize, 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 earor the auditory nerve.
Severity of Hearing Loss
Severity of a hearing loss is determined by the airconduction thresholds obtained by an audiologist during a hearingtest. Ask your audiologist the severity of your hearing loss basedon 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 CochlearImplant or Electrical Acoustical Stimulation (EAS). It wasdesigned for use with patients who have a significant amount oflow frequency residual hearing. It consists of a short electrodearray that is implanted only in the basal end of the cochlea. Theexternal equipment used with this device combines electronics tocontrol both a cochlear implant and a hearing aid, allowingpatients to make use of residual hearing.
Signal Processing
A set of rules that define how the speech analyzesacoustic signals and codes them for delivery to the cochlearimplant.
Signal Processing Parameters
A set of guidelines for processing input and translatingit into electrical signals emitted by the cochlear implant. Signalprocessing is carried out by the external speech processor. Thepossible parameters are limited by the processing limits of andpower supply to the cochlear implant. Signal processing is oftenreferred to as a coding strategy.
Single Channel Cochlear Implant System
A single channel cochlear implant system utilizes anelectrode array with only one electrode contact. This singlechannel allows for timing and loudness cues, but does not providefrequency information. Most modern implants are multi-channeldevices.
Sound
Sound can be described as a type of vibration thattravels through the air in the form of a wave of pressure. Not allsounds are speech.
Speech
Speech can be classified as orally produced sound wavesshaped by the vocal tract (oral cavity, nasal cavity, pharynx,larynx, and the respiratory system) that a listener of thatlanguage can derive meaning from. All speech is sound.
Speech Production
Ability to produce speech.
Speech Recognition or Perception Testing
Speech recognition or perception testing is one way todetermine the benefit obtained by a cochlear implant. When testingfor speech recognition, cochlear implant recipients are typicallyrequired to repeat speech stimuli (i.e., consonants, vowels,words, or sentences, etc.), either with or without the aid of visualcues and either with or without background noise to determine thepercent that can be correctly understood with the use of thecochlear implant. These scores are often compared to scoresobtained prior to implantation when individuals were wearinghearing aids.