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Flashcards in Midterm Deck (52)
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1
Q

Adult symptoms of hearing loss

A
  • need repetitions
  • tinnitus
  • “people mumble/don’t enunciate”
  • trouble on phones
2
Q

Child symptoms of hearing loss

A
  • language delay
  • artic issues
  • repetitions
  • ear pain/infections
  • difficult to obtain attention
3
Q

4 Effects of HL

A
  1. Decreased Audibility
  2. Decreased Identification
  3. Decreased Dynamic Range
  4. Decreased ability to hear in noise
4
Q

Signal to Noise Ratio

A
  • how loud the signal is compared to extra noise

- SNR should be high for successful hearing

5
Q

Variables of candidacy for amplification

A
  1. Severity of HL
  2. Speech intelligibility
  3. Lifestyle
6
Q

Lower limit

A
  • the minimum hearing loss required to benefit from amplification
    1. severity of loss
    2. stigma
    3. speech intelligibility
    4. acceptance of noise
    5. environment, needs, expectations
    6. managing HI
    7. age
7
Q

Noise Acceptance

A
  • ability to accept normal noise level of the world

- acceptable noise level test

8
Q

Options for Upper Limit of HL

A
  1. Cochlear Implants - Uni and Bi
  2. Bimodal hearing instruments - one CI, one HA
  3. Hearing instruments - Uni or Bi
  4. Bone anchored device
9
Q

Medical Concerns for HAs

A
  • tinnitus
  • sudden HL (can be treated)
  • vertigo
  • conductive HL
  • cerumen impaction
10
Q

Complaints about HA

A
  • too noisy
  • expensive
  • can’t get it in the ear
  • perception of technology
11
Q

Barriers of adoption

A
  • financial
  • minimizing need
  • stigma
12
Q

Goal of HI

A

recommend a style that can provide sufficient volume for a given individual’s HL

13
Q

Behind the Ear (Trad)

A
  • all types of HL
  • comprised of: 1 or 2 mics, receiver, processing chip, volume and battery control
  • adv: fits widest range, big battery - long life
  • dis: cosmetics, tubing difficult to change, difficult to insert
14
Q

In the Ear

A
  • mild to severe HL
  • hard plastic casing fills concha bowl and helix
  • 90dB HL
  • adv: one piece, fits wide range, easy controls
  • dis: cosmetics, changing wax guard, sent in if breaks down
15
Q

In the Canal

A
  • same at ITE without helix lock
  • mild-moderate HL
  • adv: one piece, cosmetics, easy controls
  • dis: sent in if breaks down, changing wax guard
16
Q

Completely in the Canal

A
  • mild-to-moderate HL
  • most discrete HI
  • no lower than 60-70dB HL
  • adv: cosmetics, one piece
  • dis: changing wax guard, bad for progressing HL, discomfort, wax build up
17
Q

Open Fit BTE

A
  • reduces occlusion effect
  • good for good hearing in low freq
  • customizable
  • slim tube or RIE
  • adv: cosmetics, reduced occlusion, repairs done in clinic, flexible
  • dis: change wax guard, inserting HI, falls out
18
Q

Slim Tube vs. RIE

A

slim: receiver in HA, uses thin plastic tube to deliver sound into canal *no wax guard
RIE: mic/chip/amp sit behind ear, receiver sits in ear *wax guard

19
Q

Components of Open fit

A

dome: more severe = more enclosed dome
strength of receiver: more severe = greater strength
- power vs standard receiver
vents: more vents = less occlusion

20
Q

Extended use HI

A

the lyric

  • stays in ear for 3mo
  • must have straight ear canal, not too much wax
  • close to ear drum = sensitivity
21
Q

Components of HIs

A
  1. microphone
  2. microchip (digital signal processor)
  3. receiver
    - some have RIE and t-coils
22
Q

Telecoil

A
  • special circuit designed to pick up magnetic signals emitted by phones
  • can be used with FM systems
23
Q

Earmold materials

A
  1. Lucite - hard metal, suitable for all types of HL, hazardous, discomfort w insertion
  2. Heat Cured Lucite - same as luc but hypoallergenic
  3. Polyethylene - slightly softer than 1, for mild-severe, best for allergies
  4. Formaseal - softer than 3, multicolour, durable, PEDS
  5. Silicone - soft, durable, variety of colours, non-shrink
  6. New-sil - softest, for firm ear canals, moderate durability, non-shrink
  7. Flew-canal - mix of lucite/silicone, tactile info+comfort
24
Q

Real Ear Measuring Device

A

comprised of:

a speaker, 1 or 2 external microphones, probe tube(s) and a test box

25
Q

Coupler Microphones

A

HA1 - for coupling with ITE, ITC, CIC
HA2 - for coupling with BTE
- couplers are designed to “mimic” the acoustics of the “average” ear canal

26
Q

In test box test

A
  • used for all HI except for those without custom molds
  • adv: person doesn’t need to be present for test, no movement, minimal risk of ambient noise, *PEDS
  • dis: doesn’t include patient
27
Q

On the ear test

A
  • and style of HI
  • adv: patient included, can help to troubleshoot
  • dis: patient must be still and quiet, ambient noise, doesn’t work on kids
28
Q

Probe tube measurements

A
  • 31mm for adult males
  • 28mm for adult females
  • 20-25mm for children
29
Q

Steps of HI Fitting Prep

A
  1. Make sure your microphones are calibrated
  2. Measure your probe tubes accordingly
  3. Enter the patient’s hearing thresholds into your real ear machine
  4. Pre-set hearing instrument in the test box if possible
30
Q

Speechmapping

A
  • a standardized passage of speech we use to verify hearing instruments
  • used to determine how much amplification is being received
31
Q

Prescriptive Formulas

A
  • Give us a way to determine how much volume (gain) a given individual needs for their hearing loss
  • An objective way to measure hearing instrument performance
32
Q

DSL

A
  • desired sensation level
  • based on supra-threshold prescriptions
  • from Western U
  • goal is to normalize loudness
  • peds population
33
Q

NAL

A
  • national acoustic laboratories, australia
  • threshold based prescription
  • non-linear prescriptions to maximize speech intelligibility at a volume comparable to what someone with normal hearing would need
  • achieve this by determining how various hearing losses impact speech intelligibility and the perception of loudness
  • popular with adults
34
Q

Why go above targets?

A
  • Generally long term users
  • Usually more severe hearing losses
  • Conductive component
  • Unilateral hearing aid (plus 3 dB amp)
  • Children (because learning/acquiring language)
35
Q

Why go below targets?

A
  • Extended auditory deprivation
36
Q

DSL m[i/o]

A
  • m = multistage
    1. Expansion
    2. Linear Amplification
    3. Compression
    4. Output Limiting
37
Q

Problems with Prescriptive Formulas

A
  1. Acclimatization
  2. Preferred loudness levels
  3. Dead regions
  4. Severe to Profound Hi Freq HL
38
Q

Dynamic Range

A

Range of sounds a person can hear (from highest to lowest)

39
Q

Compression

A
  • Improve intelligibility is to increase the volume of softer sounds so they are audible, while not overamplifying medium and loud level sounds
  • Compression allows you to take a wide range of input volumes and place these sounds comfortably into a smaller range
  • WHEN THE OUTPUT RANGE IS SMALLER THAN THE INPUT RANGE
40
Q

Compression Threshold

A

the input level at which the compressor switches from linear amplification to non-linear amplification
- the bend point

41
Q

Compression Ratio

A

determined by dividing the difference in input by the difference in output

42
Q

Multichannel compression

A
  • when there are several different compression ratios and thresholds across the channel
  • to optimize gain at all frequencies where more help is needed
43
Q

Non-linear Amplification

A
  • when the input:output ratio is other than 1:1

- - compression ratio

44
Q

Attack Time

A

Time it takes for compression to kick in

  • as fast as 5 milliseconds
  • change in gain between listening to quiet sounds (lots of gain needed) and loud sounds (less gain needed)
45
Q

Release Time

A

Time it takes for compression to turn off

  • sounds going from loud to quiet, compressor will turn off for more gain in output
  • 20 milliseconds to 2 seconds
46
Q

Fast Attack/Release

A
  • allows for more amplification of phonemes of speech

- better for younger/cognitively stable individuals

47
Q

Slow Attack/Release

A
  • allows speech signal to be more stable

- better for older adults

48
Q

Applications of Compression

A
  1. Avoid Distortion, Discomfort, and Damage
  2. Optimize the Residual Dynamic Range and Restore Normal Loudness Perception
  3. Maintain Listening Comfort
  4. Maximize Speech Intelligibility
  5. Reduce Noise
49
Q

Directional Microphones

A

Directional microphones allow the hearing instrument to amplify a specific area or direction with the hopes of improving speech intelligibility
All hearing instruments have two microphone ports, one at the front and one at the back

50
Q

Polar Plots

A

Omni-directional - hearing in 360
Cardioid - hearing in 180 in front of person
Figure 8 - Directly in front and behind
Hyper-Cardioid - majority is front focus, some behind

51
Q

Fixed vs. Adaptive Directional Microphones

A
  • can be set in a way that they are always amplifying in one (fixed) direction, or they can be programmed to adapt to their environment
  • Adaptive directional microphones are frequency dependent - lots of low frequency from behind? Hearing instrument might automatically switch into a cardioid pattern
52
Q

Benefits of Adaptive Microphone

A

If:

  1. dominant nearby noise source
  2. the dominant noise is stable for an extended period of time
  3. the dominant noise source is aligned in the area where the fixed directional microphone is not amplifying