Question | Answer |
number of babies born with significant hearing loss | Everyday in the US, approximately 33 babies (1 to 3 infants per 1000) are born with significant hearing loss |
most common congenital disorder in new borns | hearing loss |
The average age that children with hearing loss are identified in the US | 12-25 months of age |
number of infants born with a moderate hearing loss | estimated that 3 infants per 1000 |
number of people is US with some form of hearing loss and what percent cannot be reversed | 28 million people
80% |
number of children with hearing loss | Over 1 million children in the US have hearing losses |
percent of children 18 years and younger that have a hearing loss | 5% |
number of infants born in the US with some kind of hearing problem | 1 in 22 infants |
number of children in the US with what is termed an educationally significant hearing loss | 83 out of every 1000 children |
Among every 1000 school-aged children in the US, how many have bilateral and how many have unilateral hearing losses that may significantly interfere with their education | Among every 1000 school-aged children in the US, 7 have bilateral and 16-19 have unilateral hearing losses that may significantly interfere with their education |
number of school-aged kids that have permanent SNHL | 10 in 1000 |
NIH supports universal screening because... | Infants who receive intervention before 6 months can maintain language development commensurate with their cognitive abilities through the age of 5 |
ASHA Joint Committee on Infant Hearing supports the development of screening programs based on the following: | have access to screening using physiologic measure, if fail screening must be followedup before 3 mths old. If confirmed hearing loss, receive services before 6 moths old. If pass screening but has risks for audio prob or SLP delay, should be monitored |
Professionals working together | Pediatrician
Families
ENT doctors
Audiologists
SLPs
Educators
Early identification professionals |
hearing loss issues in Auditory Neural Development | Hear loss keeps sound from reaching the brain. If areas of brain that process audio info are not stimulated during the critical period for spch and lang, spch and lang will not develop norm. Audio stim is critical to spch perception and lang processing |
Hearing loss effects relationships between parents and children | A parent’s reaction to the hearing loss will have an impact on the outcome of habillitation.Particularly if the hearing loss is of severe to profound degree, it may affect the normal communicative interaction between parent and child |
Acceptable ambient noise level of a class room | 35 dBA |
A negative acoustic classroom environment affects: | Transmission of information
Speech perception
On-task behavior
Reading
Spelling
Social Behavior
Concentration
Academic Achievement |
A child with an educationally significant hearing loss should have one of the following: | A bilateral hearing loss of at least 20 dB PTA in the better ear
A unilateral hearing loss of at least 35 dB PTA in the affected ear
A bilateral high frequency hearing loss averaging at least 35 dB at any 2 frequencies for 2k, 4k or 6k Hz. |
pure-tone | A pure-tone is a frequency of vibration which always has the same number of cycles per second |
We test hearing by presenting stimuli through: | Air conduction
Bone conduction |
The purpose of a hearing test | To determine the type of hearing loss
To determine the degree of hearing loss |
To determine the type of hearing loss: | You need to understand the relationship between air conducted stimuli and bone conducted stimuli |
Air conduction | As sound travels through the ear canal and middle ear, it is traveling through cavities that are filled with air. |
Testing Air Conduction | begin by presenting puretone stim through air conduction when performing audiological evaluation.
The sound is presented through headphones
Sound is funneled into the ear canal
Sound then proceeds through the ear canal and hits the tympanic membrane |
travel of sound in Air Conduction | When a sound travels via air conduction, it travels throughout the entire auditory system to reach the auditory nerve.
Outer
Middle
Inner
Nerve |
Bone Conduction | There is a way to stimulate the cochlea directly, bypassing the outer and middle ear
When we use a bone conduction oscillator anywhere on the head, it stimulates the inner ear |
Frequencies at which we test for Hearing loss: Air Conduction | We evaluate a person’s ability to hear at the following frequencies by air conduction:
250 Hz
500 Hz
1000 Hz
2000 Hz
4000 Hz
8000 Hz |
Frequencies we use to test for Hearing Loss: Bone Conduction | We test a person’s ability to hear the following frequencies by bone conduction:
250 Hz
500 Hz
1000 Hz
2000 Hz
4000 Hz |
A threshold | The softest level at which a signal or change in signal can be detected |
Method of limits | the procedure audiologists use to acquire a threshold of a patient at a particular frequency |
how to test thresholds | test at a reasonably high dB & descend by 10 dB to acquire threshold. Once acquired, then proceed down 10 dB more and ascend 5 dB until we receive another response, when 2 confirmed responses at the same dB that is our recorded threshold for that freq. |
Degrees of hearing loss dB | Normal: -10 to 15 dB
Slight: 16 to 25 dB
Mild: 26 to 40 dB
Moderate: 41 to 55 dB
Moderately Severe: 56 to 70 dB
Severe: 71 to 90 dB
Profound: 90+ |
Determining degree and type of hearing loss | Always determined by the level of the air conduction threshold
The type of hearing loss is always determined by the relationship between the air conduction and the bone conduction thresholds
We chart the test results on an audiogram |
Hearing loss degree and ability to hear speech | Norm:hear soft convo.Min:have prob hearing faint speech.Mild:will miss upto 50% of a group discuss.Mod:convo +5ft may not be understood. Mod severe: miss 100% of spch info w/out amp.Severe: only hear loud noise close.Profound:depend on sight for info |
Consonants | Consonants are higher pitched than vowels (they lie more to the right on the chart).
Consonants are spoken more softly than vowels (they lie higher on the chart, in the lower decibel ranges). |
Order of Test (actual procedure) | Case History
Otoscopic examination
Impedance and reflex testing
Pure Tone Testing
Air Conduction
Bone Conduction
Speech Reception Threshold (SRT)
Speech Discrimination (WRS) |
Sensorineural Hearing Loss | Most common type of loss in adults; often permanent. Origin in the inner ear or along the auditory nerve. Damage occurs in the cochlea. Hair cells in the cochlea are damaged and cant transmit elec impulses to brain. loss can be congenital or acquired |
Sensorineural Hearing Loss
Congenital Causes | Hereditary factors (Usher’s, Waardendburgs)
Prematurity
Birth trauma such as anoxia
TORCH
Toxoplasmosis
Other (Hepatitis B,Syphilis,HIV)
Rubella virus
Cytomegalovirus
Herpes simplex viruses |
Sensorineural Hearing Loss
Acquired Causes | Ototoxic drugs
Head injury
Noise exposure
Meningitis
Encephalitis
Measles |
Conductive Hearing Loss | Problem in the outer or middle ear preventing the sound waves from reaching the inner ear
Often treated with surgery or medication |
Conductive Hearing Loss
Causes | Injury to the outer ear
Blockage of the ear canal
Infections to the outer or middle ear
Swimmers Ear (Outer Ear)
Otitis Media (Middle Ear Infection)
Perforation in the TM
Congenital Malformations
Atresia
Microtia |
Masking | When significant air bone gaps are present, masking must be performed
Masking occurs when noise is put into the opposite ear while testing the other ear
This will prevent the better ear from picking up the test signal |
Mixed Hearing Loss | A mixed loss is a SN loss w/ a conduct compon. Diso in OE & ME along with diso in IE. The conduct compon may be treated, but the SN compon usually permanent
both ACTs & BCTs will be abnorm. ACTs will be more abnorm b/c there is a diso in the OE, ME & IE |
Mild hearing loss | Soft noises are not heard. Understanding speech is difficult in a loud environment. |
Moderate hearing loss | Soft and moderately loud noises are not heard. Understanding speech becomes very difficult if background noise is present. |
Severe hearing loss | Conversations have to be conducted loudly. Group conversations are possible only with a lot of effort. |
Profound hearing loss | Some very loud noises are heard. Without a hearing aid, communication is no longer possible even with intense effort. |
Prevalence | Total number of cases of a condition in a population during a specified period of time |
sensitive | positive results = pathology |
Specific | negative results = absence of pathology |
Who screens school-age kids? | Health Departments and Education Departments are the primary agents responsible
Personnel includes:
Nurses
Volunteers
Students |
Who do you screen in the district? | kids aged 3 through 3rd grade yearly, kid needs +1 screen, have existing hearing loss, receive spe-ed services, hx colds & ear infects, have delayed spch & lang, return after major illness, sudden change in academ perform, referred by teach, new to school |
Equipment for hearing screening | Portable audiometer
Yearly calibration
Weekly check with sound level meter
Biological check every day
Should have a spare |
Individual pure-tone screening | 1000, 2000, 4000 Hz. At 20 dB.
Failure at any one frequency in either ear should be rescreened, if possible, the same day |
Static Admittance (Children) | Mean is 0.5 cm3/ml
Range 0.2-0.9 cm3/ml |
Equivalent Ear Canal Volume (Children) | Mean 0.7 cm3/ml
Range 0.3-1.4 cm3/ml |
Gradient | The distance from the peak to the positive tail of the tympanogram is bisected. The width of the tympanogram at that poin is determined in daPA
Gradient (children)
Mean 100 daPA
Range 60-150 daPa |
ME Screening | Primary Goal: Identify children at risk for significant outer and middle ear disorders that have been undetected or untreated |
Who should be ME screened? | Anyone at risk for OE or ME disorders: (Craniofacial anomalies, Native Amer heritage and Eskimo pop, Known hx of chronic Otitis Media, Exposure to excessive cigarette smoke,Learning disability, Devel delays,Spch & lang delays, SN hearing loss |
Me Screening Protocol | Tympanometry used for ME screenings. assesses the status of the middle ear system by measuring the mobility of the ear drum. The screening procedure takes approx 5 sec. May also be called acoustic impedance screening or acoustic immittance screening |
Tympanometer | An elec device used to assess ME status. Automatically varies air pressure from + to - pressure in the canal while a low frequency tone is presented to the ear. Measures the intensity of the tone as the air pressure changes and is plotted as a tympanogram |
Components of a Tympanometer | Air Pump/Manometer,Pure tone generator,Microphone, Probe tip, Ear tips, Printer |
ME Screening Procedure | 1.Use otoscope to examine ear 2.Select eartip that will seal ear canal 3.Straighten ear canal 4.Press probe firmly against ear canal creating seal 5.tymp will finish 6.Keep probe steady 7.no seal,try again 8. remove probe 9.Repeat on other ear 10.Print |
Tympanogram Measurements | Static Compliance
Ear Canal Volume
Tympanic Gradient/Tympanic Width |
Static Compliance (SC) | A measure of the height of the tympanogram (point of maximum mobility of the tympanic membrane)
Unit of measurement is mmho, cc, cm3, or ml
Also called Peak Admittance |
SC will be lower than normal if ... | the ME disorder makes the ME system less compliant (stiffer) than normal (OM or scarred eardrum) |
SC will be higher than normal if ... | the ME disorder makes the ME system more compliant (less stiff) than normal (flaccid eardrum) |
Ear Canal Volume (ECV) | A measure of the volume of air in the ear canal between the end of the probe tip and the eardrum
Unit of measurement is mmho, cc, cm3, or ml |
Smaller than normal ECV: | Probe tip is occluded by wax or is against the ear canal wall |
Larger than normal ECV: | Perforation or PE tube is open and functioning normally |
Determining Tympanic Gradient | Determined where half the peak value is on both sides of the peak. The daPa values are added regardless of their sign to determine the width |
tympnaograms Normal Values in Children | SC = 0.2 - 0.9 mmho
ECV = 0.4-1.0 cm3
TW = 60-150 daPa |
ME Re-Screening Protocol | Rescreen within 4-6 weeks if:
At age 6 years and younger: SC < 0.3 mmho or the tympanic width is greater than 200 daPa
At age 7 years and older: SC < 0.4 mmho or the tympanic width is greater than 200 daPa |
ME screening Refer | Fail rescreening. Ear drainage or blood. Ear canal abnorm such as obstructions,impacted cerumen, or foreign objects. Ear canal volume is greater than 1.0 cm3 & the tympanogram is flat
(Possible tympanic membrane perforation, unless PE tubes are present) |
To be eligible for services under IDEA | the hearing loss must adversely affect educational performance |
adverse effects of hearing loss on academics | Poor auditory discrimination
Language delay
Articulation, voice or fluency problems
Reading comprehension delay
Poor academic achievement
Social/emotional problems
At least one of these must be documented |
A child with an educationally significant hearing loss should have one of the following: | A bilateral hearing loss of at least 20 dB PTA in the better ear
A unilateral hearing loss of at least 35 dB PTA in the affected ear
A bilateral high frequency hearing loss averaging at least 35 dB at any 2 frequencies for 2k, 4k or 6k Hz. |
Adaptation | Changes made to the environment, curriculum, instruction and or assessment practices in order to provide a student equal access to learning and equal opportunity to demonstrate what is known. These include accommodations and modifications. |
Accommodations | Provisions in how kid accesses info & demon learning. The accom dont change the instruct level, content or perform criteria. Include:Presentation & response format, Instructional strategies, Time & scheduling, Architect features, Envio features
equipment |
Modifications | Substantial changes in what a student is expected to learn and demonstrate. This includes such things as:
Instructional level
Content
Performance criteria |
Minimal hearing loss | Threshold greater than 16 dB
Unilateral hearing loss
Most minimal hearing losses are caused by otitis media |
General impact of minimal hearing losses | It may affect (a child’s ability to):
Listen
Understand auditory information
Speech and language development
Behavior
Hear at a distance which affects incidental learning
Level of fatigue |
Unilateral Hearing Loss
A child may have problems with: | Hearing sounds directed to his poorer ear
Localizing
Understanding speech in noise |
Mild and Unilateral Loss/ Prevalence
Recent studies have indicated the following: | Between 5 and 7 million school age kids have some degree of hearing loss(11-15%). Prevalence noise induced hearing loss 12.5%. 1 in 20 school aged kids have min SNHL. Unilateral SNHL is the most prevalent type of hearing loss & affects 3% school age kids |
According to Dobie and Berlin, a child with a loss of 20 dB would have the following problems: | Morphological markers may be lost. Very short words in connected spch will lose loudness. Inflection or markers which carry nuances such as ?s will come through inconsistently. Kid will sometimes appear to have a processing prob, rather than a hear prob |
What is sound? | An alteration in pressure, particle displacement or particle velocity in an elastic medium
More simply put, it is vibration in an elastic medium
Vibration is the rapid back & forth motion of a single object |
Medium | An intervening substance through which something else is transmitted or carried |
Mass | A unified body of matter with no specific shape |
Elasticity | The condition or property of being elastic; flexibility. Elasticity is the ability of a body to resist a distorting influence or stress & return to original size & shape when stress removed. Elasticity increases as distance between molecules decreases |
Waves | When air molecules are disturbed, they move
They bounce off adjacent molecules
Due to elasticity, they bounce back to the point of rest
A succession of compressions and rarefactions |
Compression/Condensation | Molecules which are pushed close together
Areas of increased density |
Rarefaction | Areas of decreased density
Space that exists between the areas of compression |
Transverse wave | a transverse wave occurs when molecular motion is perpendicular to the direction of wave motion. |
Longitudinal Wave | Air molecules move along the axis of the wave itself.
Sound propagates away from the sound source.
Sound waves are longitudinal |
Sine Waves | A uniform wave that is generated by a single frequency.
Simple harmonic motion which is sometimes defined as a projected circular motion |
Cycle | a compression and rarefaction as a function of time |
four main parts to a sound wave: | Wavelength
Period
Amplitude
Frequency |
Frequency | It is the number of occurrences of any action that take place over a given time period |
Pure tone | A sound which is produced by an instantaneous sound pressure which is a simple sinusoidal function of time. |
area of compression | The part of the wave that rises above the axis |
area of rarefaction | The part of the wave that dips below the axis |
Period | The time it takes to complete one cycle is called the period
If 2 cycles are completed in one second, for example, each complete cycle takes ½ second. There is a reciprocal relationship between frequency and period
P=1/F |
Wavelength | Length is measured from any point on a sine wave, to the exact same point on the next wave
Wavelength (λ) = C (velocity)/ F (frequency)
C = fλ or f = c/ λ
Wavelength decreases as frequency increases |
Free Vibration | No external force. |
Forced Vibration | External force` |
Stiffness | the resistance of an elastic body to deflection by an applied force |
Resonance | The ability of a mass to vibrate at a particular frequency with a minimum application of external force. |
Sound Velocity | The speed with which the sound wave
travels from its source to another point |
Average velocity | distance/time |
Gasses | only when molecules collide with each other can the condensations and rarefactions of a sound wave move about. So, it makes sense that the speed of sound has the same order of magnitude as the average molecular speed between collisions. |
Liquids | Sound travels faster in liquids than in gases because molecules are more tightly packed. In fresh water, sound waves travel at 1,482 meters per second (about 3,315 mph). That's well over 4 times faster than in air! |
Solids | Sound travels fastest through solids. b/c molecules in a solid medium are closer together than those in a liquid or gas, allowing sound waves to travel faster through it. In fact, sound waves travel over 17 times faster through steel than through air. |
Phase | Any point on a sine wave (in degrees) may be compared to a standard (which is considered to be 0 degrees) |
Loudness | The physical correlate of loudness is intensity. It is measured in decibels. |
Amplitude | distance the mass moves from the point of rest. The amplitude of a sound is represented by the height of the wave. When there is a loud sound, the wave is high and the amplitude is large. |
Force | The greater the force, the greater the amplitude of a sound wave
Dynes and Newtons are units of force |
Pressure | Pressure is generated whenever force is distributed over a surface area
If the area remains constant, pressure increases as force increases
Sound pressure is measured in dynes/cm2 or we can measure it using another unit called the microPascal: µPa |
The smallest pressure to produce just audible sound to the human ear | .0002 dynes/cm2 or 20 µPa |
What are some problems faced by individuals with hearing loss? | Decreased Audibility
Decreased dynamic range
Decreased frequency resolution
Decreased temporal resolution
An individual with hearing impairment will not just have one of these problems. They will have all of these problems in some combination. |
dynamic range | a range into which all sounds fit.
Normal hearing people have a wide dynamic range
All different levels of sound from really soft to really loud fit within this dynamic range (140 dB SPL)
Hearing impaired have a reduced DR |
Decreased Frequency Resolution | People with hearing loss have a harder time separating these frequencies, because they can’t necessarily hear them as well |
Decreased Temporal Resolution | The ability to process the order in which sounds occur
When one sound stops and another begins
Also helps detect softer sounds in the midst of more intense sounds |
Hearing Aids Help | Decreased Audibility.
Decreased dynamic range.
Decreased frequency resolution. |
Hearing Aids Cant Help | Decreased Temporal resolution (No). This occurs higher up in the brainstem. |
3 Basic Principles of Hearing Aids | Gain
Output
Frequency Selectivity |
Gain | Weight Example:
Weigh yourself = 145 lbs
Weigh Dog = 30 lbs
How Much did you “gain”?
Another example:
40 db sound into the hearing aid
The hearing aid amplifies it by 40 db
“gain” is 40 db
More Technical:
Gain=output-input |
Output | Light Bulb Example - 60 Watt bulb
Only put out 60 watts
May put out less (dimmer switch)
Can not put out more than 60 dB no matter who tries
More Technical:Output=Input+Gain |
What is a Hearing Aid | A small electronic device worn in or behind your ear that is designed to amplify sounds so that a person with a hearing loss can listen, communicate, and participate more fully in daily activities |
number of people who show benefit from a hearing aid | Only about one out of five people who show benefit from a hearing aid actually use one |
Analog hearing aids | have a microphone that picks up sound and converts the sound into electrical signals, which are amplified and delivered to your ears |
Digital hearing aids | convert incoming sound waves into digital signals that are manipulated according to an individual's hearing levels and listening needs. Once the signal has been manipulated, it is amplified and delivered to your ears |
benefits of Digital hearing aids | More flexibility in programming
Greater precision in fitting, management of loudness discomfort, control of acoustic feedback, and background noise reduction |
Hearing Aid Components | Microphone
Amplifier
Receiver
Battery |
Microphone | The hearing aid receives sound through a microphone, which transduces the sound waves from acoustic energy to electrical energy and sends them to an amplifier
Two types of microphones:
Omni-directional
Directional |
Omni-Directional Microphone | Amplifies sounds around the hearing aid user
Desirable for environments where the incoming signal and noise can be heard around you
` |
Directional Microphones | Amplify sounds coming from a specific direction (in front of you) and reduces the noise coming from behind you
Directional microphones provide a better signal to noise ratio when compared to omni-directional microphones |
Amplifier | Increases the level of the electrical signal sent from the microphone, which is then delivered to the receiver
The signal is amplified according to the user’s amplification needs and the hearing aid settings |
Receiver | Transduces the electrical energy from the hearing aid amplifier back into sound that is sent to the middle and inner ear |
Batteries | The hearing aid battery delivers power to the electronic parts of the instrument
Hearing aids generally run on zinc air batteries
A hearing aid battery begins to discharge as soon as the protective seal has been removed. |
Replacing the battery | 1. Open battery door by swinging door open with finger
2. Take out old bat
3. Peel “tab” off of new bat
4. Hold between your thumb and forefinger w/ (+) side up
5. Slide or push into bat door. Dont place battery directly inside aid itself
6. Close do |
Other Aid Controls | Turning the hearing aid "on" or "off"
Changing the volume
Switching to the telecoil
Switching between omni- and directional-microphone settings
Switching to different programs
According to the type of environment/ listening situation |
Telecoil | Small magnetic coil in aid that allows users to receive sound through circuitry of aid rather than through its microphone
makes it easier to hear convo over the telephone
Can be used in larger settings with assistive listening devices like FM systems |
Hearing Aid Styles | Body Worn
Behind the Ear (BTE)
Receiver in the Canal (RIC)/Receiver in the Ear (RITE)
In the Ear (ITE)
In the Canal (ITC)
Completely in Canal (CIC) |
Body Worn Hearing Aids | One of the first models of hearing aids
Includes:
Earpiece or custom earmold worn in the ear
External box which contains the components of the hearing aid and is worn around the waist or in a pocket
Cord that connects the earmold to the case |
Behind The Ear (BTE) | A small plastic case, which contains the parts of the hearing aid, sits behind the outer ear and connects to the earmold via a plastic tube
Considered among the most powerful hearing aids
Used by all ages for mild to profound hearing loss |
Receiver in the canal/ Receiver in the Ear | Similar to a BTE, however the receiver is located in the earmold or covered by a dome that goes in your ear or ear canal |
In the Ear (ITE) | All parts of the aid are contained in a shell/earmold that fits into outer part of ear
Larger than canal aids and easier to handle
Used in mild to severe hear loss
Not recommended for young kids b/c their ears are growing & aid would need replacing fre |
Canal Hearing Aids | All parts of aid are contained in shell/earmold that fits into ear canal
b/c of small size, often tough to adjust and remove
Not recommended for young kids
For mild to moderately severe hear loss
Two styles:
In the canal (ITC)
Completely in canal |
In the canal (ITC) Aid | hearing aid is made to fit the size and shape of a person’s ear canal. |
Completely in canal (CIC) Aid | hearing aid is nearly hidden in the ear canal |
Components of BAHA | Processor: picks up sound vibrations
Abutment: Connects sound processor and implant and transfers sound vibe from processor to implant
Titanium Implant: Placed in temporal bone behind the ear & transfers sound vibe to functioning cochlea |
Speech Processors | Intenso
Small, digital, head worn
Cordelle
Consists of an ear-level transducer and a body worn unit
BP 100
First programmable sound processor
Better sound quality |
Criteria for a Baha | Unilateral or bilateral
conductive or mixed hearing loss
Single Sided Deafness
Receive no benefits from traditional air conduction hearing aids
Not FDA approved for children younger than 5 years of age |
conductive & Mixed hearing loss Criteria | Bone conduction thresholds better than 45 dB
Air bone gap is more than 30 dB
Speech discrimination score is better than 60% |
Single Sided Deafness Criteria | Unilateral sensorineural deafness
One ear has a profound SNHL, the other ear has thresholds less than or equal to 20 dB HL
Speech recognition scores below 20% in the impaired ear and above 80% in the contralateral ear |
How does BAHA work in SSD? | The Baha device is placed on the deaf side behind the ear and transfers sound through bone conduction, stimulating the cochlea of the normal hearing ear |
Osseointegration | Occurs from the response of the bone when it is in contact with titanium
The implant fuses with the bone, providing an internal anchor for the implant
Takes up to 3 months in adults and 6 months in children |
How to Connect/Disconnect the Sound Processor BAHA | Connect:
Push processer in using an angled approach
Disconnect:
Bend the sound processor in any direction to release it |
BAHA Batteries | Type 13 zinc air batteries
In order to check the speech processor after the battery has been changed:
Turn up volume and blow into microphone
If you feel the vibrations, sound processor is on and working |
Implantable Middle Ear Hearing Devices (IMEHDS) | Small surgically implanted device that transduces acoustic energy to mechanical energy, which is delivered to the middle ear
Works similar to a hearing aid |
who uses Implantable Middle Ear Hearing Devices (IMEHDS) | Used by those who do not benefit from traditional hearing aids
Not satisfied with hearing aids
Feedback
Occlusion effect
Distortion
Cannot wear hearing aids or earmold
Stenosis |
Implantable Middle Ear Hearing Devices | 2 Devices are currently approved by the FDA
Med-El Vibrant Soundbridge
Soundtec Direct System |
Med-El Vibrant Soundbridge | First middle ear implant to be approved by the FDA in 2000
Mechanical energy delivered directly to the ossicles
Enhances natural vibratory motion
Eliminates many of the acoustic issues associated with traditional amplification:
Occlusion and feedb |
Components Med-El | Speech Processor
Magnet
Implant
Conductor Link
Floating Mass Transducer |
Speech Processor Med-El | Worn behind the ear
Held in place by a magnet which connects the processor to the implant
Contains a microphone that transduces acoustical energy to electrical energy and sends this energy to the implant
675 zinc air battery is needed |
Implant Med-El | Internal device that receives electric energy from the processor and sends the signal down the conductor link to the floating mass transducer |
Floating Mass Transducer Med-El | Small titanium drum wrapped with gold wire
Transduces elec signals into mechanical vibe which sets the middle ear in motion conducting the signal to the inner ear
Attached to incus if SNHL or
Attached to stapes or round window if mixed or cond hear lo |
Candidacy Criteria Med-El | Adults older than 18
Bilateral moderate(in low frequencies) to severe SNHL
Conductive or Mixed hearing loss
Word recognition of 50% or better |
Exclusion Criteria Med-El | Retrocochlear Pathology
Active middle ear infection
Tympanic membrane perforation associated with recurrent middle ear infection
Inability to follow-up
Skin conditions that would be affected by the pressure from the processor |
SOUNDTEC® Direct Drive Hearing System | Approved by the FDA in 2001
Uses electromagnetic energy which vibrates the ossicles of the middle ear leading to the perception of sound |
SOUNDTEC Components | Behind the ear sound processor
Earmold/Coil Assembly (ECA)
Implant |
Sound Processor SOUNDTEC | Sits over the external ear
Receives and amplifies the sound vibrations
Microphone in the processor transduces the acoustic signal into electric signals which are received by the earmold/coil assembly |
Earmold/Coil Assembly SOUNDTEC | Earmold in the ear canal that contains the coil
Transduces electrical signals from the sound processor and creates an electromagnetic field with the magnetic implant |
Implant SOUNDTEC | The magnetic implant directly drives the ossicles as it receives electromagnetic energy from the Earmold/Coil Assembly
Attached to the middle ear ossicles at the incudo-stapedial joint |
Soundtec Candidacy Criteria | For ages 21 to 80 years
Bilateral moderate to severe sensorineural hearing loss
Normal middle ear anatomy
Dissatisfied with hearing aids
Score of ≥ 60% on word recognition test
Hearing aid use for more than 6 months |
Soundtec Exclusion Criteria | Conductive hearing loss
Retrocochlear pathology
Ear infect
Tympanic membrane perforations associated with recurrent middle ear infections
Previous middle ear surgery that has destroyed the integrity of the ossicular chain
Malformations of external ea |
Why is a cochlear implant different than a hearing aid? | A cochlear implant bypasses the absent or damaged cells and stimulates the auditory nerve directly by converting acoustic energy to electrical energy |
Candidates for Cochlear Implants | Adults
Children 12 months or older
Severe to profound SNHL
Receive little or no benefit from hearing aids
Healthy enough for surgery |
Procedure for Cochlear Implant | Surgical placement of internal component is performed under general anesthesia
Typically, the surgery is done on an outpatient basis and the individual goes home on the same day. Sometimes an overnight stay is necessary |
Fitting the external component of cochlear implant | Following a 3-6 week recovery period, the first fitting, or “initial stimulation” takes place
audiologist sets specific parameters of stimulation, setting levels that are comfortable
Aural re/habilitation key for use of implant |
cochlear implant Programs | represents the setting that the audiologist has determined best meet the client’s needs. The sound processor can store up to 3 programs. This allows the device to be used in different listening environments. |
cochlear implant Sound coding strategy | method used to transcribe acoustic sound into an electrical code
CIS (Continuous Interleaved Stimulation)
SAS (Simultaneous Analog Stimulation)
MPS (Multiple Pulsatile Sampler)
HiRes (HiResolution Sound) |
cochlear implant T-level | threshold level which is the stimulation level that is perceived as very soft |
cochlear implant M-level | Most comfortable level-represents the stimulation level that is perceived as most comfortable |
cochlear implant RF level | radio frequency power level required to maintain the proper communication between the internal and external components during normal operation of the system |
cochlear implant Lock | the system is “locked” when external component is properly sending a signal to the internal component |
How to put on a body worn processor cochlear implant | Verify processor is off
Check battery pack is in place
Turn volume all down
Set sensitivity to user setting
Place headpiece over implant
Turn on processor appropriate program
LED blinks appropriately for battery charge & stops flashing confirm lock |
Battery Charge Status cochlear implant | 3-4 blinks of LED indicate that battery is fully charged
2 quick blinks means it is sufficiently charged
1 blink = needs replacement or re-charge |
Lock Status cochlear implant | After the blinking battery sequence LED will flash approximately once per second until the headpiece is properly placed over the implant and the successful communication is established
The LED will stop flashing to indicate that the system is locked |
check microphone cochlear implant | Once you are in lock status, observe the green LED light (the other was red) as you snap your fingers or say “bah, bah, bah.”
Ask child to repeat Ling 6 sounds
Ah, Ooh, ee, sh, sss,mmm |
Factors influencing efficacy cochlear implant | Age at implantation
Previous auditory experience
Presence of any additional handicapping conditions
Teaching emphasis on auditory learning |
Auditory Milestones | 0-6mo. Startles loud sound
6-8mo. Babbles
9 mo. Responds to name
12 mo. First word
15 mo. Jabbers with some real words thrown in
18 mo. 50 word vocab, start word combinations, can identify body parts
24 mo. 200+ spoken words, follows simple directio |