Contraction of the middle ear muscles in response to intense sounds, which has the effect of stiffening the middle ear system and decreasing its static acoustic compliance.
Acoustic Reflex
Measures the effect of middle ear muscle contraction on the TM stiffening.
- Stimulation intensities vary from 70-100dB HL.
- Tested freq. 500, 1000, 2000,4000
- normally occurs in both ears
provides useful diagnostic tool in measuring middle ear neuro functioning and audiotory sensitivity.
Acoustic Reflex
reflex is stimulated and measured in the same ear.
Ipsilateral
when the stimulus is in the tested ear and the probe is in the opposite
Contralateral
- ex. right contralateral= right ear stimulus and probe tip in the left ear.
the measurement of middle ear pressure determined by the mobility of the membrane as a function of various amounts of positive and negative pressure in the external ear canal.
Tympanometry
3 types of tymps
Tymp (A) As and Ad
Tymp B
Tymp C
synonymous with normal middle ear function.
- peak within normal limits and pressure within normal limits
Type: Tymp A
abnormal stiffness in the middle ear system
- peak within normal limits but compliance is abnormally low
Tymp As
a flaccid TM with high amplitude
- may indicate excessive scar tissue or disarticulation of the middle ear bones.
Tymp Ad
restricted TM mobility, possibly fluid or some pathological condition. Cerumen can also be the cause due to a plugged probe tip or comlete blockage.
-compliance is abnormally low
Tymp B
abnormally negative pressure in the middle ear cavity.
- usually indicative of upcoming or resoloving otitis media
- compliance usually normal
Tymp C
PTA
Pure tone average
MCL
Most confortable level
UCL
Uncomfortable level
SDT
Speech Detection Threshold
SRT
Speech Reception Threshold
WRS
Word Recognition Score
OAE
Otoacoustic Emission
AABR
Automated Auditory Brainstem Response
ABR
Auditory Brainstem Response
one ear
unilateral
both ears
bilateral
one ear is aided
monaural
- hearing aid or cochlear implant
both ears aided
binaural
Efforts designed to restore a lost state or function.
- includes educators, psychologists, social workers and rehabilitaion counselors.
- Process to help the patient
Aural Rehab
First known deaf educator
Pedro Ponce De Leon
learned finger spelling and sign language with speechreading
- opened a school for the deaf
Thomas Gallaudet
promoted more oral methods speechreading - electrical
Amplification
Alexander Graham Bell and Horace Mann
Pioneer of audiology
Raymond Carhart
HIS stands for
Hearing instrument specialist
- dispensed hearing aids in the 1940's and 50's
- audiologist just tested and recommended
It is estimated that ______ percent of Americans who could benefit from hearing aids are not using amplification.
80%
What is the reason 80% of people need HA and don't get them?
-lack of early identification/ intervention
- working order of personal amplification
- access to resources
- vanity issues
- life experiences
- improper fitting of instruments
charateristics of Hearing loss
Degree and configuration
time of onset
type of loss
auditory speech recognition ability
impairment present at birth or prior to the development of speech and language
Prelingual Deafness
- before age 5
- importance of early intervention
the loss occurs after about age 5
Postlingual Deafness
-speech and education possibly affected
those who lose hearing after their schooling is complete.
Deafened
- unable to comprehend speech with hearing alone
- social and emotional effected (profound or worse)
outer or middle ear damage
conductive
impairment of inner ear or nerve
Sensorineural
combination of SNHL and CHL
Mixed
level at which the patient can detect a sound is present
Speech Detection Threshold
(they have awareness of sound)
Level at which the patient can repeat or identify the stimulus
Speech Reception Threshold
- more freq. specific they can repeat it back
WHO
World Health Organization
CORE
Communication status
Overall participation variables
Related Personal Factors
Enviromental Factors
Assessment Procedures
C - in core
communication skill
- impairment and activity
- audiometric tests and questionaires used to assess awareness of hearing loss
- Evaluate communication and language
Assessment Procedures
O - in CORE
Overall Participation Variables
- participation aspects of hearing loss
- Psychological
- social - family, spouse, social class and lifestyles
- vocational - position, responsibility and compentence
- educational
Assessment Procedures
R - CORE
Related Personal Factors
- personal attitude
- personalities- Type I, II, III, IV
- must modigy attitude to continue in rehab process
- also include age, race, gender, habit, coping style, upbringing
strong positive attitude
Type I personality
essentially positive, hard to fit hearing loss- hard to configure
Type II personality
negative attitude, but will cooperate at times
Type III personality
reject hearing aids and rehab process
type IV personality
Assessment Procedures
E - CORE
Enviromental Factors
- indv. aspects - physical features of enviroment as well as personal contacts
- services - social structure, work, transportation
- systems- laws regulation and rules
- Acoustical environment they encounter
Things to take into consideration in regards to psychosocial aspects of hearing impairment with the patient.
- adjustment period
- acceptance
- Lifestyles
- Unseen varibles
- Expectations
deaf with a little d means
bilateral profound SNHL
Deaf with capital D means
cultural identification with the Deaf community.
learned behavior from input, feedback and peer reactions
Self-concept
- need approval from those around them
- kids w/hl may have poor self concept-due to communication difficulties and decreased interaction with peers
- Cosmetic issues may begin to appear
Purpose of amplification
- to make speech and enviromental sounds audible to the hearing impaired person
-Optimize intelligibility and sound quality
- Ensure loud inputs are not uncomfortable or distorted
Responsibility of Fitting
- cost effective fitting and appropriate fitting
- adjust the HA to the patients specific type and HL
- Adjust the hearing aids precisley for the patients specific listening needs.
- Provide follow up
- Facilitate other aspects of aural rehab
Hearing aids need a __________ electroacoustic analysis from the manufacturer.
yearly
Hearing aid companies provide _________ that vary in length and time.
warranties
- renewal of warranty after expired for a fee.
Turning off the hearing aid prevents __________ for removal or insertion?
feedback
T or F
Its ok to use alcohol or oil to clean aids?
False
T or F
During the first few week, use the hearing aids in a normal, quiet, everyday environment?
True
If you didn't want to turn the hearing aid off to put in someone's ear, what else could you do to prevent feedback?
Open the battery door then insert into ear
T or F
Hearing aids are regulated by the FDA and are medical prostheic appliances.
True
Circut design in Hearing aid technology offers what? 2 things
1. New signal processing algorithms
2. Multiple channels of signal processing
Digital/programmable hearing aids offers what? 3 things
1. All current technology is programmable
2. Use digital processing of the signal
3. Programmed by using a computer
What are Probe-microphone measures used for?
- used to measure the reliablity of the output of hearing aids at the level up to the tympanic membrane
- allows for a precise, freq. specific fitting of the hearing aids
- Provide a verifiable measurement for evaluation.
What is computerization?
-Allows the hearing instrument to be programmed through specific fitting software for patient verification.
- Allows the audiologist to see adjustments made to the hearing aid in real time
-Freq. specific adjustment capabilites
Waht is the AudioScan Verifit used for?
It is for the hearing aid itself.
-for checking the hearing aid
-scans and verifies
- checks acoustic info
What role does the internet play in hearing aid technology?
- provides the consumer/patient access to current technology trends
- created tech savvy patients of all ages
- Increased patient expectations of technology.
What is the initial Hearing aid process?
1. Audiological examination
2. Counsel regarding results
3. Discuss the types of hearing aids
4. Discuss the types of hearing aids
- make and model are important, but more important to find one that fits their lifestyle
5. Take an ear mold impression
What do you go over with the patient when discussing proper maintenance and care of the hearing aid?
1. how it works
2. replacing batteries
3. cleaning instrument
4. check thier dexterity
- remember there will always be an adjustment period
- warn them about loudness levels and enviromental sound they were missing
What do you do in a hearing Evaluation??????? Not sure about this question>
1. Program to the patient's hearing loss
2. Electroacoustic analysis and probe microphone measures
3. "Aided" sound field testing
- recorded with an "A" on audiogrm.
4. Provide the patient with a before and after view of their test results
Patients have a _____ day refund policy required by federal law.
60
You are allowed to return your hearing aids for a full refund before how many days?
30
- minus exam and fitting fees
BTE
behind the ear
- most powerful ha you can get
OTE
over the ear
- no ear impression needed
- mostly for mild hearing loss
- cannot be used on profound patients
ITE
in the ear
-fills up concha
- largest one for in the ear
- not as powerful but more cosmetically appealing
ITC
in the canal
- middle sized (in the ear) hearing aid
CIC
completely in the canal
- hard to see
- convenient but not a lot of power
Basic components of a hearing aid. (4)
1. Microphone
2. Amplifier
3. Reciever
4. Battery
Sound waves enter here and converts the acoustic signal(sound waves) into electrical signal?
Microphone
What increases the strength of the electrical signal (makes it louder)
Amplifier
What converts the amplified electrical signal back into amplified acoustical signal (sound waves)?
Receiver
What provides electrical energy to power the hearing aid?
Battery
What do the following control features stand for?
M
O
T
M- microphone
O - turns the ha off
T - if present activates the telecoil
What enhances use of hearing aid on the telephone? Also picks up "leaks" electromagnetic signals and converts them into acoustic energy.
Telecoil
What are the features for the volume control?
- Controls the loudness
- toggle switch, rotating wheel or remote control.
- some devices automatically adjust volume.
- So patients may prefer a volume control, even if its disabled.
What is the purpose of amplification?
1. to make speech and environmental sounds audible to the hearing impaired
2. Optimize intelligibility and sound quality
3. Ensure loud inputs are not uncomfortable or distorted
What is the difference in dB between input and output of the hearing aid?
Gain
- remember the input signal plus the aid gain equals the total output
input signal
+ aid gain
= total output
What is the response or gain at the frequencies it amplifies?
Frequency Response
Information about the frequency range of the frequencies the aid effectively amplifies is called ___________.
Bandwidth
Controls and Features
- Frequency Specific Gain
1. Control the amount of amplification in specific frequencies
2. Frequency band control
MPO stands for what?
Define MPO
Maximum Pressure/Power Output
- the maximum output that the hearing aid will ampligy up to its "upper limit"
Compression is also known as?
Automatic Gain Control (AGC)
______________ limits the amount of maximum power output (MPO)?
Compression
(Compression)
AGCo happens _________ the amplifier?
After
(Compression)
AGCi monitors input, the signal ________ before its amplified?
Before
An old form of compressing the signal by essentially cutting off the peaks of the signal is called what?
Peak Clipping
Distortion is not present with AGC?
T or F
False
It is still present with AGC.
The most expensive hearing aids can reproduce an exact amplified reproduction of the orginal signal?
T or F
False
Directional Mic Technology does what?
1. allows for better signal to noise ration (SNR)
2. Can be single directional or omnidirectional
3. May have a button to change between the 2 or aid may do this automatically
4. Circuitry is dependant on the degree of loss and the size of hearing aid.
CROS stands for?
Contralateral Routing of the Signal
- for patients with an unaidable hearing loss in one ear(mic) and normal to near normal hearing in the opposite ear (receiver)
BICROS stands for?
bilateral Contralateral Routing of the signal
- for an unaidable ear, to an aided ear on the oppisite side.
- single amplifier and receiver to better ear.
BAHA stands for?
Bone Anchored Hearing Aid
- Surgically implanted behind the ear into the mastoid area
- for conductive hearing loss
Ideal patients for the BAHA?
- congiential atresia or longstanding middle ear disfunction.
- also for single sided deafness, but not so much for these patients.
How does the BAHA tranfer sound?
Takes sound from the direct BC from the BAHA sends it to the cochlea of the good ear.
A biomedical device that is surgically implanted to bypass the middle ear and stimulate the 8th nerve directly?
Cochlear Implant
What type of hearing loss would a patient with a cochlear implant have?
sensorineural- hair cells not working properly.
- cochlear implants- very invasive surgery
Steps for taking an ear impression:
1. perform otoscopy
2. use otolight to place eardam just beyond the second bend of the ear canal
3. mix base and catalyst together
4. use a syringe and inject material in the ear canal until the concha and helix are filled up.
5. Lift the pinna up and back to remove hardened impression material
You create an ear mold from an ear impression?
T or F
True
What is the process for ear molds?
1. impressions are sent to a company and the ear molds are made
2. Couples the hearing aid to the patients ear using a specific type of tubing
3. Provides support and stability for BTE's, OTE's and CI's
- for CI's used for retention purposes only
4. Directs and modifies the sound depending on the style and features that are chosen.
What are some examples of Assistive Listening Devices?
alarm clocks
tv headsets
telephones
personal communicators
door bell alarms
some dectector aids
(some visual aids to get their attention.)
What may be the most important aspect of successful use of hearing aids?
A tight fit
A small hole drilled into the canal portion of the shell/earmold?
vent
What are the 3 primary reasons for a vent?
1. Allows for low frequencies to escape from the ear canal.
- larger vent= more low frequency attenuation- (larger- less amplification)
2. Release pressure to decrease "plugged up" feeling
3. Allows for normal input of unamplified sounds.
What is the purpose of Hearing Aid Dampers?
Muffles (dampens) the peaks
What are hearing aid dampers made from?
Mesh screens, cotton, lambs wool
Where are the hearing aid dampers placed?
In the receiver of a custom insturment.
What do hearing aid acoustic horns do?
Enhances high frequency gain especially in the 3000 to 4000 Hz range (increases amplification)
- progressively increase the internal diameter of the earmold tubing or custom shell sound bore
- size of the horn is limited to the size of the earmold/shell
What are the 5 common sizes of batteries?
5, 10, 13, 312, 675
- smaller batteries don't last as long and are not as powerful
- small # of the battery smaller size of the battery
All hearing aids must operate under this standard?
American National Standards Institute
Selecting the HA Candidate
3 things you need to know:
1. Degree of loss - depending on the severity of the hl and their pure-tone threshold
2. Degree of Communication Disability- How the patient percieves their communication difficulties
3. Motivation- is the patient will to wear aids and accept aural rehab process.
Preselection Measurements
What is used to predict how much gain is needed in the prescriptive fitting formula?
Pure-tone threshold
Preselection Measurements
Use of pure-tones or Narrow Band Noise to obtain how loud of a sound can be tolerated by the patient at various frequencies is called _________?
Loudness discomfort levels
What is the ability to understand speech in the presence of background noise?
Speech-in-noise
Hearing aid style depends on:
the patients dexterity, canal size, medical conditions, cosmetic appeal, degrees and configuration of hearing loss.
What is meant by gain and frequency response?
power of the hearing aid
- gain and output are manipulatied by prescriptive formulas
T or F
You should trust the manufactures fitting formulas because that are validated by NAL and DSL research?
False
What do multiple channels do?
allows the signal to be broken down into separtate catergories by frequency range for processing.
- provies a more appropriate adjustment of gain and compression
- helps modify for a patients specific hearing loss.
What does multiple memories(programs) mean?
they are specific memories(programs) that can be tuned with differnet fitting parameters for varying environmental situations.
- ex. restaurant, music, crowd noise etc.
The difference between the patient's LDL and threshold for that signal (pure-tone or speech)
Dynamic Range
- provids a guide to fitting range
- helps determine limiting of MPO
Most effective in improving SNR based on spatial location.
Directional Technology
- works best when the desired sound input is directly in front of the patient
-
Directional provides better SNR than omnidirectional
When hearing aid channels analyze the sound input and when its determined to be noise, the aid automatically decreases the gain to that channel, this is called what?
Automatic digital noise reduction
Provides the patient ability to increase the gain to make soft sounds more audible?
Adaptive Feedback Reduction
- allows for more open fitting
- hearing aid identifies the frequency of feedback and applies gain reduction
Besides improper fit of a hearing aid, what is another major cause of hearing aid rejection?
Feedback
What are the advantages of binaural fittings?
Two is better than one
- increased gain
- improved localization
- sound quality
- better speech understanding in the presence of noise.
-
When listening with 2 ears we are able to hear sound at a lower level compared to one ear, this is called what?
Binaural Summation
What are the advantages of binaural summation?
- advantages for low level sounds is 3 dB better
- Suprathreshold advantage is as much as 10-12dB better (high frequencies)
- helps you localize better
More advantanges of Binaural Hearing
1. Binaural summation
2. Intensity/Frequency- can hear smaller changes in both.
3. Sound localization- localize sound better
4. Time difference- timing in localization
5. Speech discrimination- better in the presence of background noise.
Who are Probe Mic Measures used on?
babies
- most reliable method in assessing realtime hearing aid adjustments and performance.
H- stands for
hearing expectations
I - stands for
Instrument operation
O - stands for
occulsion effect
B - stands for
batteries
A - stands for
acoustic feedback
S - stands for
System troubleshooting
I - stands for
insertion and removal
C- stands for
Cleaning and maintenance
S - stand for
Service, warranty and repair
HIO basics hearing expectations
adjustment periods and realistic expectations.
HIO instrument operations
ability to turn the aid on/off, change programs, adjust volume, activate telecoil, and use telephone
HIO basics
what is it called when you have a plugged up feeling/ head in a barrel?
occlusion effect
HIO basics
Batteries
types, sizes, where to buy, battery life.
Ability to insert/remove battery
HIO Basics
Acoustic Feedback
Demonstrate when feedback is appropriate
HIO Basics
System Troubleshooting
review hearing aid manual
HIO Basics
Insertion and removal
Properly insert and remove hearing aid
HIO Basics
Cleaning and maintenance
cleaning tools, wax removal, no fluids allowed, not to drop the hearing aid.
HIO Basics
Service, warranty and repairs
warranty explanation of coverage, repair policies, when to service the aid and the process of repairs.
- refer to booklet or audiologist
Purpose of follow ups
1. Measure functional gain
2. Measure LDL with patients normal setting
3. Repeat self assessment questionaires
4. Check general care and maintenance of hearing aid
5. Check data logging
What do you need to remind the patient about acclimatization?
that it takes several weeks to months for the brain to adjust to new sounds
For pediatric patients when prefitting use _________ results to plot audiogram for fitting?
ABR
What does RECD stand for?
Real ear to copuler difference.
- very important - metal coupler
- re-evaluate often
- obtain behavioral measurements as soon as possible- aided and unaided
