First Exam Flashcards
(179 cards)
1
Q
Elisabeth Kübler-Ross 5 psychological stages of grieving
A
1) denial
2) anger
3) bargaining
4) depression
5) acceptance
2
Q
Stages of change
A
begins at precontemplation contemplation preparation action mainenance (can end here or go to) relapse back to precontemplation
3
Q
informational counseling
A
commonly used by AUDs clinically
*provides info such as describing audio and explaining HAs
4
Q
what makes for good informational counseling?
A
- speak clearly and at a slower rate
- be relaxed
- offer visual demonstrations
- offer written material for the pt to take home
5
Q
personal adjustment counseling
A
- used to guide the pt to coping w/ HL
- aud and pt develop relationship based on trust and by understanding the pt’s perspective
- views pt in a holistic manner
6
Q
what make for good personal adjustment counseling?
A
- acknowledge the courage of the pt for making the decision to come into your office
- ask open-ended questions so patient takes ownership of the visit
- emotionally connect to the pt; ask questions about pts life and experiences
- helps build trust
7
Q
problem recognition in motivational interviewing
A
- pt recognized they have a hearing problem
* can ask pt “do you think you have a HL?”
8
Q
elicit expression of concern in motivational interviewing
A
- elicit response from pt that indicates they are concerned about their HL
- can ask things like “what worries you the most about your hearing loss?”
9
Q
intention to change in motivational interviewing
A
- determine if the pt is ready to accept HAs
* can ask questions like “what makes you think you need hearing aids now?”
10
Q
self-efficacy in motivational interviewing
A
- determine if pt can make a long-term commitment to change
* can ask things like “what is keeping you from seeking help?”
11
Q
pre-selection considerations for HAs
A
- pt attitude and motivation
- has pt acknowledged their HL?
- what are pt’s communication needs?
- does the HL keep the pt from participating in life activities?
- self-image
- realistic expectations
- fear of not being able to care for HAs
- cost
- influence of others
- hearing impairment
- tinnitus
- stigma and cosmetic concerns
- age
- cognitive ability
12
Q
8 red flags for ear pathology and hearing disorders
TRY AND FIND THE 8TH
A
1) visible deformity of the outer ear
2) visible evidence of significant cerumen accumulation or foreign body in the ear canal
3) any history of active drainage from ear within the previous 90 days
4) any history of sudden HL within the previous 90 days
5) any acute or chronic dizziness
6) ear pain or discomfort
7) air bone gap on the audiogram of more than 15 dB at 500, 1000, and 2000
13
Q
is it necessary to obtain medical clearance before fitting hearing aids?
A
it is not longer enforced by the FDA to obtain medical clearance except for pediatrics (under 18)
14
Q
what conditions is it best to obtain medical clearance for when fitting HAs?
A
- sudden or rapidly progressing HL w/in last 90 days
- otalgia
- tinnitus (recent onset or unilateral)
- unilateral HL or large asymmetry of unknown origin w/in last 90 days
- acute or chronic dizziness
- headaches
- conductive HL
- –ABG = or > than 15dB at 500, 1000, & 2000
- otitis externa or otitis media
- –history of active drainage w/in last 90 days
- impacted cerumen
- foreign body in ear canal
- atresia or deformity of external ear
- any peds
15
Q
what things are important to note about a HL from seeing the audio?
A
- degree
- configuration
- type
16
Q
what to know about speech testing and hearing aid success
A
results of speech tests (in quiet or noise) are poorly correlated to success with hearing aids and do not predict candidacy or success for the pt.
*we do speech tests because it gives an idea how the pt may perform in the real world and as a counseling tool
17
Q
list speech in quiet tests
A
- SRT
- WRS
- –NU-6, CID W-22, CNC
18
Q
list speech in noise tests
A
- quickSIN
- HINT
- R-SPIN
- AzBio Sentence Test
19
Q
loudness discomfort level (LDL) definition
FINISH THIS WITH WORD DOC
A
- measures the pt’s level of discomfort
- establishes the top end of the pt’s dynamic range
- AKA
- —-uncomfortable listening level (UCL
- —-Threshold of discomfort (TD)
20
Q
LDL procedure
A
- each ear individually
- use speech or pure tones
- Cox Contour loudness anchors
- frequently test at 500 & 2000 Hz using pulsed tones (says test at 2 different freqs)
- begin at 55 dB HL
- increase in 5 dB steps
- 2 test runs for each freq and take average
- if the 2 runs are more than 10 dB apart, run a third and then take average
21
Q
list the pre-fit questionnaires
A
- Hearing Handicap Inventory for the Elderly or Adults (HHIE or HHIA)
- Client Oriented Scale of Improvement (COSI)
- Glasgow Hearing Aid Benefit Profile
- Abbreviated Profile of Hearing Aid Benefit (APHAB)
- Expected Consequences of Hearing Aid Ownership (ECHO)
22
Q
HHIE/HHIA
A
- handicap profile
- hearing handicap is the pt’s perception of a problem or limitation in daily communication associated with hearing loss
- assessed perceived effects of HL on emotional and social status
- 0 (no handicap) to 100 (total handicap)
- —0-16%= no handicap
- —18-42%= mild -moderate handicap
- —44% or more= significant handicap
23
Q
COSI
A
- client orientated scale of improvement
- benefit scale
- open-ended communication needs assessment tool
- pre and post fit
- target goals
- —Pt writes 5 specific needs/goals
- —can monitor degree of change over time
24
Q
Glasgow
A
- benefit scale
- evaluated effectiveness of rehabilitation services for adults with hearing impairment
- 4 predetermined items
- –pt responds by using a likert scale
- –0=N/A
- –1= no difficulty
- –2= only slight difficulty
- –3= moderate difficulty
- –4=great difficulty
- –5= cannot manage at all
- 4 pt nominated items
25
APHAB
* abbreviated profile of hearing aid benefit
* another benefit scale
* pre fit and 2 weeks post fit
* 24 items with statements describing specific scenerios with and without hearing aids
* 7 point likert scale
* pt can also indicate:
- --hearing aid experience level
- --daily hearing aid use
26
ECHO
* expected consequences of hearing aid ownership
* measures pre fit expectations of hearing aid use
* produces a global score and four subscales
- --positive effect
- --service and cost
- --negative features
- --personal image
* primary use: determine any unrealistic expectations the pt may have
27
Acceptable noise level (ANL)
| MUST FINISH FROM WORD DOCUMENT
* is a success predictor
* ANL quantifies a listener's willingness to accept background noise
* obtained by: minding the most comfortable level (MCL) for speech, then finding the background noise level (BNL) the pt will put up with while listening to speech
* ANL=MCL-BNL
28
Factors which influence ANL (acceptable noise level)
* the intelligibility of the primary stimulus
* the primary talker gender
* the number of background talkers
* the use of central stimulants (ADHD meds for example)
29
ANL (acceptable noise level) is unrelated to
* speech understanding in noise
* amplification use
* hearing sensitivity
* reverberation
* gender of the listener
* age
30
goals of HA fitting
* appropriate amplification across frequency regions
- --AKA audibility of sounds across freqs
* sounds should be perceived as the appropriate loudness
* good sound quality/fidelity
* meet pt's communication needs
- --improve intelligibility
* sound awareness
31
asymmetric HL
* significant interaural differences in threshold sensitivity
* interaural difference in discrimination ability
32
monaural HL
* unaidable in one ear
| * one ear that has normal hearing or can be aided
33
bilateral fit for asymmetrical HL pros and cons
pros:
* binaural advantage
* localization, binaural squelch
* always want to express that bilateral fit is best
cons:
* perceptual confusion with a distorted signal from one side
- --signal from better ear is better quality and signal from poorer ear may be distorted
34
unilateral fit for asymmetrical loss in the better ear
* can possibly reach optimal aided performance
| * can achieve close to normal hearing in one ear
35
unilateral fit for asymmetrical loss in the poorer ear
* can create a more balanced auditory experience
* can bring level of hearing up to level of better ear
* will not achieve optimal hearing performance
36
when to fit the better ear with asymmetrical HL
* HL is mild
| * only weak sounds will be inaudible when unaided
37
when to fit the poorer ear with asymmetrical HL
* audibility for many sounds will improve when aided
| * aided right ear may also help with binaural sqeulch
38
other considerations when fitting only one ear and choosing which ear to fit with an asymmetrical HL
* pts often prefer the poorer ear b/c of the large disadvantage when speech arrives from the poorer side and the better ear was aided
* which hand has better dexterity?
* which ear displays better speech discrim in quiet, in noise, or significant advantages on a dichotic speech test?
* are their complications with either ear canal?
* is pt routinely in a situation where the talker is always on the same side?
* does pt prefer to use the telephone on a specific side/ can they communicate on phone unaided?
39
CROS option for monaural HL
* ear with normal hearing
- --receiver, receiver coupled to ear using open dome
* ear with hearing loss
- --mic mounted on poorer ear; referred to as the satellite microphone
40
BiCROS candidacy and set up
* candidates= pts who have an asymmetric bilateral HL and are unaidable in the poorer ear with aidable loss in the better ear
* ear with better hearing
- --mic, amplifier, and receiver
* ear with poorer hearing
- --mic mounted to send signal to better hearing ear
41
transcranial CROS candidacy and how it works
transmits a signal from one side of the hear to the other via bone conduction
* candidacy: pts with single sided deafness
* non-functional ear: high powered HA; sound is transmitted via BC to normal hearing ear
42
goals of a HA fitting
* appropriate amplification across freq regions
* sound should be perceived as the appropriate loudness
* good sound quality/fidelity
* safe listening environment
* meets pt's communication needs
43
list the advantages of binaural input
1) localization
2) head shadow effect
3) binaural squelch
4) binaural loudness summation
5) ease of listening
6) sound quality
7) preservation of hearing ablities
44
localization
* helps create a safe listening environment
* helps with spatial organization
* horizontal localization
* vertical localization
* cues for localization:
- --interaural time difference
- --interaural intensity difference
45
Interaural time difference (ITD)
helps with localization
* sound arrives to the ear closer to the source before the ear further from the source
* also results in interaural phase difference
- --dependent on the degree of azimuth and freq of the sound
* ITD is greatest at 90 and 270 degrees azimuth
* ITS and IPD are strong cues fro low freq sounds <1500 Hz
46
interaural intensity difference (IID)
helps with localization
* sometimes referred to as interaural level difference
* the head is an acoustic barrier and causes intensity differences between ears (head shadow)
* dependent of degree azimuth and freq of sound
* IID is a strong cue of high frequency sounds
- --can attenuate high freq sounds by 10-15 dB
47
head shadow effect advantage to binaural hearing
acoustic phenomenon
| *if listening with both ears, you can benefit from head diffraction effects by attending to the ear with better SNR
48
binaural squelch (advantage of binaural hearing)
* select ear with better SNR when speech and noise are spatially separated
* central auditory nervous system processes difference in time and intensity cues
* better for low frequency sounds
49
binaural loudness summation normal hearing vs hearing impaired
is capacity to centrally integrate sound received at each ear
* normal hearing:
- --loudness of a sound is greater if heard in two ears
- --at or near thresholds: 3 dB louder
- --at MCL: about 6 dB louder
- --at higher intensities: up to 10 dB louder
* hearing impaired:
- --slightly less loudness summation
- --at mid levels: about 4 dB louder
- -- less at threshold, more at higher intensities
50
ease of listening (advantage of binaural hearing)
subjective benefit
51
sound quality (advantage of binaural hearing)
* just noticeable differences (JNDs) for intensity and frequency are smaller
* negative effects of reverberation on speech intelligibility are less noticeable
52
preservation of hearing abilities (advantages of binaural hearing)
* auditory deprivation
- --systematic decrease over time in auditory performance associated with reduced availability of acoustic information
- ---study says 40% of monaural HA wearers had reduced WRS in unaided ear after asymmetrical stimulation
53
list of disadvantage of bilateral HA fitting
* cost
* binaural interference
* self image
* wind noise
* aid management
* occlusion effect
54
describe bone conduction HAs
bone conduction oscillator produces vibrational output
* must adequately couple transducer to hear
* similar to traditional air conduction HAs in that they have:
- --mic
- --amplifier
- --tone controls
- --advanced features
- --linear and/or nonlinear gain applications
- ------however they have a bone oscillator instead of a receiver
55
transcutaneous bone conduction
signal is sent across the intact skin
56
candidacy for bone conduction HAs
* conductive HL
- --chronic infection or inflammation of EC
- --congenital ear malformation (atresia, microtia, anotia) that precludes a traditional HA
* mixed HL
* single sided deafness (SSD)
57
med-el adhear
* non-surgical bone conduction device
| * sounds transmitted onto bone via the adhesive adapter that is placed on the skin behind the ear
58
how is the output of a bone conduction HA expressed
in dB re which is reference force of 1 microNewton due to the fact the output is mechanical vibration instead of sound pressure
59
measuring gain in bone conduction HAs
similar to traditional AC HAs
* must verify the gain is appropriate for the pt
* acousto-mechanical sensitivity level
- ---output force level minus input SPL=directly analogous to gain
60
how to measure the output force level of a bone conduction HA
use an artificial mastoid which is created to simulate the human skull so that the impedance matches the human skull
*accelerometer measures the vibration
61
advantages of bone conduction HAs
* direct bone conduction works independently of the ear canal and the middle ear
* sound can be clearer than sound from traditional air conduction HAs
* note: max CHL=60-65 dB
- ---can have max CHL and still use a bone conduction HA
62
disadvantage of bone conduction HAs
* transducer placement
* coupling techniques
* little to no interaural attenuation
* hard-wired cables of a traditional BC HA can be a place of break down in the wires
* attenuation from skin/tissue and limitations of BC HA transducer
* limitations with measuring the output of the aid
63
candidacy for bone anchored hearing solutions
* mixed HL or conductive HL
* bilateral atresia
* ossicular disease
* post-op ear defect
* chronic inflammation or infection of EAC/ME
* SSD
* over 5 years of age
64
softband and soundArc options of bone conduction HAs
* really no need for traditional hard headband bone conduction aids because of bone anchored options
* but the softband and sound arcs are used on:
- --kids under 5
- --for trial periods for at least 2 weeks before surgery
- --with those who don't qualify or refuse surgical implantation
65
pre-op counseling for bone anchored hearing solutions
* appropriate expectations are extremely important
* primary concern can guide expectations:
- --audibility
- --chronic inflammation/infection of me or eac
- --single sided deafness
- --severe mixed HL
* multidisciplinary teams of aud, surgeon, slp, and educational professionals are used
66
surgical procedure for bone anchored hearing solutions
* small incision is made behind ear
- --titanium screw placed
* osseoinegration
- --bone grows around the screw
* percutaneous coupling
- --device goes through the skin=direct connection to the skull through skin
- --transcutaneous coupling can cause 10-15dB attenuation compared to percutaneous (especially in high freqs)
67
process of sound delivery of bone anchored hearing solutions
* direct bone conduction meaning skips outer and middle ear
* process of sound delivery
- --mic
- --sound processor
- --abutment
- --implanted screw
68
how bone anchored hearing solutions actually work
* 2 pieces of ferrite
- --magnetic material w.out permanent charge but not permanently magnetized
* coils of wire around 1 ferrite
- --when you apply voltage to coil, it magentizes the ferrite
* permanent magnet
- --used to bias the system
- --so the ferrite will come together and then repel to create the vibration
69
when to do unilateral fit of bone anchored hearing solution
* unilateral CHL or MHL (goes on the impaired side)
| * single sided deafness (again goes on the impaired side)
70
when to use bilateral fit with bone anchored hearing solution
* bilateral CHL or MHL
* w/ bilateral use consider:
- --dexterity
- --cosmetics
- --hair growth
- --employment
- --driving
- --telephone use
71
BAHA fitting ranges
* baha 5 sound processor= BC up to 45dBb
* BAHA sound power=BC up to 55 dB HL
* BAHA super power= BC thresholds up to 65 dB HL (this has processor separate like cochlear implant)
72
oticon bone anchored hearing solution
* oticon Ponto
| * has titanium abutment attachment
73
sophono bone anchored hearing solution
* sophono Alpha 2
- --abutment free device
- --= 45 dB bone conduction thresholds for indicated ear
- --= 20dB bone conduction thresholds in better hearing ear for single sided deafness
* (i think this one uses a magnet)
74
Med-El bone anchored hearing solution
* med-el bonebridge
* CHL or MHL
* older than 5
* CT scan showing anatomy appropriate for placement
* no retro cochlear or Central auditory disorder
* motivated
* skin friendly because no abutment needed?
75
advantages of bone anchored hearing solutions
* all components in 1 casing
* less visible than conventional BC HAs
* reported greater physical comfort
* better freq response than conventional BC aids
* effective for significant CHL and some MHLs
76
disadvantage of bone anchored hearing solutions
* titanium fixture or implanted magnet
* surgical procedure
* changing BC thresholds may render BAHS ineffective
* clinic sites supporting BAHS use is few, though is growing
* difficult to measure how much gain pt is receiving (difficult with verification)
77
candidacy for middle ear implants
* 18 or older
* moderate to severe SNHL
* minimum speech discrimination score of- %
* pts who have difficulty with conventional aids
- --feedback, occlusion effect, comfort issues, etc. that cannot be fixed
* 30 days with appropriately fit HAs
* normal ME and TM anatomy
* normal ET function
- ----note that new reports show pts wit ME issues can benefit from a middle ear implant
78
contraindications of middle ear implants
* recurrent otitis media
* complete mastoidectomy
* pediatrics
79
how do middle ear implants work
* transmts acoustic energy to a mobile structure within the middle ear space
- --causes movement of the ossicular chain and/or prosthesis
* the input is acoustic signal
* the output is vibrational/mechanical motion
* vibrational transducer
* partially or fully implantable
*note cost is 9,000-37,000
80
piezoelectric transducer
transmits an electric current through a piezoceramic crystal
* when voltage is applied, material is deformed or changes shape (bands, flexes, contracts, expand)
* contraction and expansion of material depends on direction of current
* voltage applied ultimately causes mechanical motion and moves most of the ossicular chain
81
available piezoelectric device
Envoy Esteem
* fully implantable
- --piezoelectric sensor and driver
- --sound processor
* sensor is attached to incus and senses vibrations from TM via attachment to incus
* converts mechanical vibrations to electrical signals and transmits to sound processor
* sound processor amplifies and filters the signal and sends it to the driver
* driver converts modified electrical signal back to mechanical energy and vibrates the stapes
- ----fits losses from 40-90
82
advantages of piezoelectric transducer
* small design
* small components
* completely implantable
* reports after FDA trial
- --SRT improved by 11.4 dB
- --WRS significantly better in 56% of pts
- --27dB mean improvement in PTA
- --quality of life statistically significant improvement
83
disadvantages of piezoelectric transducer
* output and frequency response limitations
* disarticulation of ossicles
* cost
* initial surgery
* battery replaced via surgery every 6-9 yrs
* reports after FDA trial:
- ---40% taste disturbance
- ---14% tinnitus
- ---7% transient facial pareses or paralysis
84
electromagnetic transducer middle ear implant
includes a magnet and induction coil
* electrical current is transmitted through an induction coil
* electromagnetic field oscillated, moving nearby the magnet
* movement of magnet causes movement of the ossicular chain
85
med-el's electromagnetic middle ear device
* vibrant soundbridge by med-el
* partially implantable
- --vibration ossicular prosthesis (VORP)
- ----contains in internal coil
- ----magnet and receiver module
- ----floating mass transducer (FMT)
- -------electromagnetic transducer that consists of an electromagnetic coil that encases a small permanent magnet
86
how does the med-el vibrant soundbridge work
* external sound processor
- --mic, signal processor, transmitting coil, center magnet and battery
* sound processor picks up acoustic signal and converted to electrical signal
* electrical signal is transmitted via an amplitude-modulated carrier to the VORP
* signal is then demodulated and sent via conductor link to FMT (now a mechanical signal)
87
carnia system electromagnetic middle ear device
* currently not available in the US
* four components:
- --implant
- --programming system
- --charger
- --remote control
88
ototronic maxum electromagnetic middle ear device
* partially implantable
* only two components:
- --implant: neodymium-boron (NdFeB) magnet placed at the incudostapedial joint
- --external processor: contains digital sound processor and electromagnetic coil
89
advantage of electromagnetic transducer
* can generate more energy than piezoelectric MEI
| * ossicles stay intact
90
disadvantages of electromagnetic transducers
* coil and magnet must be in close proximity
* some devices require deep insertion of canal device
* surgery
* cost
91
benefits of middle ear implants
* higher levels of gain
* less distortion
* less feedback
* no need for EM's (mostly)
* fully implantable (Esteem)
92
disadvantages of middle ear implants
* surgical procedure
* lack of flexibility if pt is dissatisfies with result
* audiologist's familiarity w/ device and programming
93
5 main time periods of hearing aids
* acoustic era
* carbon era
* vacuum tube era
* transistor era
* microelectric/digital era
94
list the 5 essential components of HAs
* microphone
* amplifier
* receiver
* earmold or means to provide sound to the ear canal
* power source/battery
95
behind the ear (BTE)
* two piece HA (ear hook and casing)
* mic, amplifier, and receiver mounted in casing
* custom earmold or soft dome attached to ear-hook
* standard tubing and slim tube options available
* fitting range: mild to profound
96
pros of BTEs
* can fit most hearing losses
* technology progresses with patient
* can provide large amounts of gain/output
* directional microphone technology
* less prone to feedback
* less prone to moisture and wax buildup
* cosmetically appealing
97
cons of BTE
patient perception
| *difficulty with localization
98
receiver-in-the-ear (RITE) and receiver-in-the-canal (RIC)
* open fit technology
* basically a small BTE (the only difference is the receiver is located in the ear canal)
* custom earmold or open dome attached to receiver wire
* fitting range: mild to severe HL (depends on power of receiver and appropriately fit earmolds)
99
pros of RITE and RIC aids
* cosmetically appealing
* new technology
* multiple programs
* comfortable
* dispense off of shelf
100
cosn of RITE and RIC
* fit range is more limited (best for high frew HL)
* may have more feedback issues
* gain limitations
* features may be limited
101
In-the-ear (ITE) full shell devices
* full shell
* completely custom
* fitting range: mild to profound
102
pros of full shell ITEs
* can have many features due to large size
* many venting options
* easy insertion and removal
* easy maintenance
103
cons of full shell ITEs
* cosmetic appeal
* can provide a large amount of gain, but limited compared to BTE
* potential feedback
* no directional audio input
104
in-the-ear: half shell
fitting range: mild to severe
105
in-the-ear: half shell pros
* more discreet than full-shell
* some venting options
* may be easier to manage for some pts (insertion and removal)
106
in-the-ear: half shell cons
* more limited fit range
* may not have as many features due to size
* venting options are more limited; greater difficulties with the occlusion effect
* greater likelihood of feedback
* may be more limited in ability to connect to external sound sources
107
in-the-canal (ITC) and completely-in-canal (CIC)
*fitting range: mild to moderately-severe
108
pros of ITCs and CICs
* cosmetically appealing (discreet)
| * provides better directionality and localization because of where the mic sits in the ear canal
109
cons of ITCs and CICs
more likelihood of feedback
* less gain/output
* less room for venting (> occlusion effect)
* no room for additional features
* size 10 battery (yellow sticker); hard to manipulate and does not last very long
* problems with moisture and wax; may need a lot of repairs
110
deep seated devices
* phonak lyric 3= extended wear hearing aid
* fitting range: mild to profound
* pt must buy a subscription
111
pros of deep seated devices
* better localization because location of mic
* better directionality
* pt doesn't have to remember to do anything with device for 3 months
* FDA cleared 2001
* pt does have some control over volume
112
cons of deep seated devices (phonak lyric)
* not custom
* expensive (just as much as BTE over a course of a year)
* not waterproof, but water resistant
* stays in the ear canal for three months at a time
* risk of infection is higher
* not comfortable
* older version was analog; now more sophisticated but not as much as a traditional hearing aid
113
deep seated devices starkey soundlens (invisible in canal)
fitting range mild to moderately-severe
114
pros of starkey soundlens deep seated devices
* custom fit
* better natural directionality because of where the mic sits in the ear canal
* less likelihood of feedback when the patient talks on the phone
* cosmetically appealing (invisible)
* sound quality is more natural (subjective reports)
115
cons of starkey soundlens deep seated devices
* not many features available due to size
* issues with moisture
* pt may push the device too far into the canal
* possible OC effect
* may cause cerumen impaction
116
3 essential functions of ear molds
1) amplified sound sent to the ear canal (via the sound bore
2) the direct sound path between the ear canal and the air outside the head is controlled (via venting)
3) physical retention of the hearing aid
117
7 factors to consider when determining an appropriate ear mold for a patient
* style
* material
* ease of insertion
* adequate retention
* sufficient acoustic seal
* comfort
* correct sound direction
118
advantages of acrylic earmold material
* little deterioration or shrinkage with time and use
* easy to grind, drill, re-tube, and buff
* smooth surface helps with insertion and removal
* easy to clean
* advantage of the soft acrylic: decreased leakage
119
disadvantages of acrylic earmold material
* will not compress to insert past narrow areas of the canal
* leaks easily when the ear canal changes shape (hard acrylic)
* not recommended for children due to rapid growth and need for remakes often (also bc potential injuries)
* potential for injury when struck, especially if it shatters
120
advantages of vinyl earmold material
* comfortable
| * some vinyls soften at body temps and harden at room temps, helping with insertion and acoustic seal (less feedback)
121
disadvantages for vinyl earmold material
* shrinks, hardens, and discolors with time (needs replacing annually)
* tubing may be difficult to replace; may need a tube lock
122
advantages of silicone earmold material
* comfortable (especially for tight fits and long canal fits)
* little shrinkage with time
* low incidence of allergic reactions
* better acoustic seal
123
disadvantages of silicone earmold material
* impossible to grind/buff
| * tubing cannot be glued, a tubing lock is required
124
earshells for custom hearing aids considerations
* adults and children with the same HL will have different gain output (amplification) requirements because of difference in ear canal volume
* ear canal volume is smaller in children than adults resulting in higher ear canal SPL
* also with deep-canal fittings (regardless of shell style) there is an increase in gain, output, and HF emphasis (due to its deep-seated location)
125
parallel vs y vent (aka diagonal)
*parallel is preferable
*only use y vent if there is no other alternative
because it created two problems: 1) decreases high frequency gain
2) makes high frequency feedback more likely
126
goal of vents
reduce OE without causing feedback and without decreasing low frequency gain too much
127
acoustic horn
provides a way to boost gain in the high frequencies (Libby horn)
128
dampers
* used to decrease gain and maximum output frequencies corresponding to resonances in the sound bore (smooth frequency response from the tubing, earhook, and earmold)
* the further down the tubing the damper is placed the more effective it becomes at damping 1,3,and 5KHz
* most of the time, dampers are placed in the earhook to smooth out the bump in the frequency response that occurs at 1000Hz
129
difficulties associated with unilateral hearing loss
* localization of sound and speech
* hearing speech or warning/emergency signals from poorer side
* difficulty understanding speech in noisy environments
* reduced audibility
130
what is CROS
* contralateral routing of signals
* transfer of sound from one side of the head to another
* transferred wirelessly or with aids connected by a cable wire
131
candidacy for CROS
* unaidable hearing in one ear
- --profound hearing loss
- --very poor word discrimination
- --loudness tolerance issues
* normal hearing or aidable hearing in the other ear
(unilateral HL, asymmetric HL, or single sided deafness)
132
how CROS is set up on the ears
* ear with normal hearing:
- --receiver coupled to ear with open dome
* ear with hearing loss:
- --mic mounted on poorer ear; referred to as the satellite mic
133
candidacy for BiCROS
* pts who have asymetric bilateral HL
* unaidable hearing in poorer ear
* hearing loss in better ear
134
set up for BiCROS
* ear with better hearing: mic, amplifier, and receiver
| * ear with poorer hearing: mic mounted to send signal to better hearing ear
135
what is transcranial CROS and candidacy
* transmits a signal from one side of the head to the other via bone-conduction
* candidates: pts with single sided deafness
136
how does a transcranial CROS work?
non functional ear has a high powered hearing aid, and sound is transmitted via bone conduction to the normal hearing ear
*really just close off ear hook and blast output of the aid to the point that it vibrates
137
microphones basic and what type of microphones do hearing aids use?
* mics convert acoustic energy to electric energy
* waveform of electrical signal produced by microphone is identical to waveform of incoming acoustic signal
* **hearing aids use electret microphones
138
what 4 things do electret mics contain
* inlet port
* diaphragm
* back-plate with electret coating
* field effect transistor (FET)
139
how does an electret mic operate?
* sound enters through inlet port
* this sound reaches one side of the diaphragm
* pressure fluctuations cause diaphragm to move up and down
* small air spaces separates the diaphragm from a rigid metal place (the back plate)
* the back plate is coated with thin Teflon material called electret; it also has holes to allow movement of air through it
* electrical charges attract opposite charges onto diaphragm and back-plate
* when sound forces diaphragm and electret to move away or towards one another, this varies the voltage between back-plate and diaphragm
* the vibrating diaphragm turns the sound wave into an electrical voltage
* the electric voltage is then sent to the microphone amplifier (FET)
140
frequency response of microphones
* relatively flat frequency responses
* frequency response can vary by design of mic
* low cuts are a design feature on hearing mics used to attenuate low frequency environmental sounds
* helmholtz resonance= boost gain-frequency response by 5 dB for frequency range of 4000-10000Hz
141
list 6 imperfections of microphones
* break down
* random electrical noise
* vibrations
* internal feedback
* overload/distort
* wind noise
142
new MEM technology microphones
microelectromechanical system (MEMS) technology
* silicon technology
* operates similarly to electret microphones
143
advantages of MEMS technology
* extended battery life
* stability across environments
* stable frequency responses
144
omni-directional microphones
equally sensitive to sound pressure from all directions
145
function of amplifier
makes a small electrical signal into a larger electrical signal
146
what technology is used in an amplifier? (4 things)
* transistor
* diodes
* capacitors
* circuit board
147
compression amplifier
* automatic gain control (AGC)
| * automatic volume control (AVC)
148
tone controls
* gain of amplifier varies with frequency
* achieved by using filters
* can adjust based on pt's HL
149
serial structure filter structure
* contains one low-pass and one high-pass filter
* sound passes through the filters in sequential order
* common in analog hearing aids
150
parallel structure filter structure
* the filters divide the frequencies into bands or channels
* each frequency band is amplified independently of other bands
* disadvantage= distortion
151
serial-parallel structure filter structure
* used to overcome the distortion produced by parallel structures
* frequencies are analyzed in a parallel bank
* appropriate filter is determined and sent to the serial filter for processing
152
basic function of a receiver
*convert the amplified electrical signal into an acoustic signal
153
how does a receiver work?
* electrical current passes through the coil
* current flowing through coil creates a temporary magnet
* current alternating back and forth attracts the armature; armature is also attracted and repelled by 2 permanent magnets
* armature vibrates within the receiver casing and is linked by a drive-pin connected to the diaphragm
* the vibrating armature pushes the drive-pin up and down which ultimately vibrates the diaphragm and creates the acoustic signal
154
battery sizes large to small
* 675 blue
* 13 orange
* 312 brown
* 10 yellow
* 5 red
155
basic way sound travels to and then out of hearing aid
1) microphones collect environmental sounds and converts it into an electrical signal
2) electrical signal is then sent to the amplifier where the small signal becomes a larger signal
3) the now larger electrical signal can be adjusted by filters
4) it is then sent to the receiver where it is converted back into an acoustic signal for the patient
156
basic use/purpose of telecoil
allow audio sources to be directly connected to HA
| *helps filter out background noise
157
what devices can a telecoil be used with
telephones,
FM systems (with neck loops)
induction loop systems
158
what type of technology do telecoils use?
| and what three things are involved in this technology
near-field inductive transmission or near-field magnetic inductive coupling
1) copper coil
2) magnetic field
3) process of induction to occur
159
what is induction?
process of an electrical current inducing a voltage in a coil
160
what can create a magnetic field?
* telephone receivers (land lines)
| * induction loops
161
how does a T-coil operate?
* telecoil picks up the electromagnetic leakage from the telephone receiver
* the oscillating magnetic field flows through the coil
* once the coil picks up the magnetic field, it generates an electric current
* the electrical current is proportional to the acoustic signal
* the electrical signal is sent to the amplifier and ultimately ends up at the receiver where it is converted back to an acoustic signal for the pt
162
why is communication improved when using the T-coil when the mic is off
1) background noise and reverberation are reduced
2) frequency response of telecoils is smoother than when HA is acoustically coupled to telephone
3) no feedback between the HA and telephone
163
manual T-coil program
pt would push button or switch toggle to engage t-coil
164
automatic t-coil program
HA detects a magnetic field produced by phone and automatically switches to t-coil setting
165
M+T or MT t-coil program
Ha mic is on while t-coil is engaged
| *good for pts who need acoustic and magnetic signals simultaneously or in quick succession
166
limitations of t-coils
* if using a cell phone they have to be HA compatible (must emit a magnetic field specifically for use by HI people; ANSI requires field strength of at least 125mA/m)
* proper orientation of handset (pts may have a hard time getting the handset in the correct location for the HA to switch to t-coil mode)
* some phones produce low-level magnetic fields, so it may be harder for the t-coil to sense the magnetic field
* vertical orientation of the t-coil inside the HA is better for induction loop systems but not phone use
* sources of undesirable magnetic fields can engage t-coil (florescent lights)
167
Direct audio input (DAI)
* direct connection of external sound source to the HA via a cable
* DAI with FM receiver
- --must have a "boot" on the HA to activate DAI
- --HA must have DAI compatibility before the FM boot will work
168
streaming connectivity
* newer technology
* wirelessly streams audio signal to HAs
* this technology is available on any device, not limited to just BTEs
* Transmitter (Tx) transmits directly to HAs
* signal could be transmitted using:
- --FM signal (150-220 MHz range)
- --proprietary wireless method (850-900 MHz range)
- --bluetooth (2.4 GHz)
* from sound source to streamer: proprietary wireless or bluetooth
* from streamer to HA: near-field magnetic induction (1-10 MHz)
169
iPhones and HAs
* HA compatable
| * uses acoustic phone program or uses bleutooth the stream calls/music/audiobooks directly to HAs
170
volume control
* adjusts gain or the maximum power output (MPO) depending on where they are located within the HA circuit
* more common on older technology
171
analog volume control
rotate wheel and it will stop in full on or off position
172
digital volume control
no stopping position
| beeps to indicate volume control settings
173
volume control on custom devices
* roll wheel towards nose to increase volume
| * roll wheel away from nose to decrease volume
174
volume control on BTEs
* roll up to increase volume
| * roll down to decrease volume
175
who shouldn't have volume control?
* pediatrics
* if pt didnt have volume control on old HAs then do not order one for new HAs
* pts who have limited manual dexterity
176
remote controls for HAs
* allows the pt to control how the HA works without having to touch HA
* remotes typically have a volume control, but may also have:
- --t-coil options
* directional vs omnidirectional mic options
* on-off switch
* switch between programs
177
pushbuttons & toggles
allow for multi-memory or multi-program HAs
178
why do we need multiple programs?
* environmental change
- --for optimal listening, HAs should have different amplification characteristics for each environment
* depending on circumstances
- --listener may want to optimize intelligibility
- --or optimize comfort
179
commonly used programs for HAs
* quiet environment
* speech-in-noise
* comfort-in-noise
* T-coil/acoustic phone
* music
