Hearing Aid Candidacy Flashcards
5 Requirements of a successful Fitting
- General Attitude of Pt- Does pt think that they need HA’s?
- Age- Dexterity issues, Coping with loud or chaotic environments
- Cosmetic Appeal- Pt will only wear HA’s if it meets their cosmetic and personal wishes
- Use Time- Assessing a usage time but is not a full requirement of successful fitting
- Degree of Loss- determines both use time and satisfaction of HA
Is slight for some and significant for others, sustained attention is difficult
Mild Loss
Hears someone close without difficulty , speech shows articulation omissions , substitutions and distortions. They do benefit from HA’s
Moderate HL
Patient understands loud conversational speech, but have difficulty in groups or noise. Can gain excellent benefit from a HA.
Moderately severe HL
Hear loud sounds or a voice close to the ear. They even identify noises or vowels but miss consonants. A HA lets them function for ordinary purposes
Severe HL
Do not rely on hearing for communication. The HA cannot compensate for the hearing Impairment. It maintains contact with the environment and allows them an awareness of what is going on around them, using auditory clues
Profound HL
Any method describing gain at each frequency is a___
Prescriptive Method
Any method comparing one product, slope, frequency, output or other measurement with another is a___
Comparative Method
To increase or decrease specific frequencies in the speech range unit the response is no longer flat.
PMI- Pressure Measuring Instruments (comparative Method)
Emphasizes speech discrimination scores in quiet and in noise, and aided SRT and tolerance thresholds using several different models of HA’s for comparison.
Carhart Procedure (Comparative Method)
This concept involves providing enough gain at each frequency to correct the pure tone sensitivity to normal or 0dB. Is usually not an ideal method.
Mirroring the Audiogram (comparative method)
Gives a practical guideline suggesting the gain requirement to reach MCL through the HA is approx. 1/2 the pure tone ANSI thresholds.
The Half Gain Formula (prescriptive method)
1/3 HTL at each frequency, minus 5dB at 250Hz and 3dB at 500Hz
Libby Procedure (prescriptive Method)
1/3 HTL at 500Hz and 1/2 HTL at 1k-4K Hz
Lybarger Method (prescriptive Method)
The head blocks sound arriving from the unamplified side, causing high frequency attenuation. LF’s travel around the head easier than HF’s
Head Shadow Effect (monaural fitting)
Occurs with prolonged use of amplification to one ear. The ear without amplification loses its ability to discriminate with measurable differences in a 4-5 year period while discrimination scores remain stable over time
Auditory Deprivation (Mon. Fitting)
7 Contra-indications to Binaural Fitting
- Degradation Effect
- Poor Binaural Fusion
- One Ear has a small Dynamic Range
- Diplacusis
- UCL very low in one ear
- Patients feeling psychologically closed off or plugged with 2 HA’s
- Physical factors such as multiple disabilities or motor skills dysfunction.
When binaural discrimination scores are poorer than with the better ear alone.
Degradation Effect
Audiometric thresholds are greatly asymmetrical and often longstanding
Poor Binaural Fusion
A patient who perceives a different pitch on each ear is a poor binaural candidate
Diplacusis
Uses one body worn hearing instrument with a Y shaped cord and a receiver and earmold in each ear. Thresholds must be symmetrical.
Bilateral Fitting
Uses one complete hearing instrument on the better ear and a second microphone on the non functional ear.
BiCros
For a person with unilateral loss or a non- functional ear and normal hearing on the better ear
Cros
Are useful for bilateral atresia, chronic draining ears or massive conductive components with sensorineural involvement
Bone Conduction Fitting
What are some potential reasons for unaidable ears
- Profound sensorineural loss where maximum amplification cannon reach Pt’s threshold
- Severe or profound mixed losses, like atresia
- An abnormally small dynamic range (5dB)
- Abnormally low UCL’s
- Berry poor discrimination that degrades the better ear
- Ear under medical treatment
- Otolaryngologist recommends amplification be avoided
The basic problem for clients with an asymmetrical hearing loss is
Discriminating speech from the side of the head with no usable hearing
An inability to locate sound
Hearing in the presence of noise
Some patients with binaural amplification can experience
Degradation effect
Dexterity of a Pt’s fingers enter into the choice of instruments because of difficulty in
Inserting earmold into the ear
Replacing the battery
Adjusting the volume or any of the controls of the HA
A bone conduction instrument should be used when
The patient has chronic otitis media
Pressure Measurement Instruments (PMI’s) are
Built to the sound pressure standard of 20 micropascals
Properly selected hearing instruments should allow:
The pt to wear an instrument at a comfortable loudness level
Improved communication ability of normal conversational speech in noise
Better hearing, aided, than unaided
Slope of loss can determine a successful fitting. A most favorable slop is:
Flat or gradually falling
Calculations of amplified sound to Pt’s MCL do not include
Reserve gain
Calculating prescription formulas are compared to:
Specification sheets
The follow fitting requires amplification to two ears
Binaural
