impressions Flashcards
solid/body worn
-full shell with pres stud attachment for body worn
-fully fills concha = good acoustic seal for high powered aids
-can be hard/ hard with soft tip
Limitation- can ONLY be worn with body worn aids
full shell
-used with BTE aids
-fully fills concha-> good acoustic seal
-good for severe to profound
-can have pics and colours
-can be hard/soft or hard acrylic with soft tip or all soft +non allergenic
Limitation- not suitable for mild to mod as it occludes too much of the ear
-not as cosmetically appealing
carved shell
-suitable for severe to profound losses
-moulds to the ear creating a good acoustic seal
-more cosmetically appealing than full shell
-lightweight
-recommended for temporo mandibular joint movement
Limitations - people with dexterity issues may struggle with insertion and removal
-more prone to damage as a thinner layer of material
skeleton mould
-used with BTE aids
- for mild to mod +mild conductive losses
-lighter than shell moulds, fills the edges of the concha, carved to create a ‘handle’
-easier to insert than shells for some patients BUT also easier to break
-more discreet
-usually acrylic or acrylic with soft tip or non allergenic alternatives
-Limitations - not suitable for severe to profound losses as sound will escape
open mould
-usually for very mild losses, tinnitus patients, CROS aids and for use as cochlea implant retainers
-very similar to skeleton but more handle carved away
-Gap handle(gap in the middle), top of the handle is missing
-All open moulds have a large vent incorporated to maintain concha resonance
-lightweight and can be brittle
-Limitations - not suitable for severe to profound losses as sound will escape
meatal tip
-suitable for very low powered aids/ mild hearing losses only
-consists of the part which fits inside the meatus ONLY
-may be easier to insert for people with poor dexterity
-can be tubed with a standard tube or a slim tube
-acrylic, soft acrylic or non allergenic alternatives
-now largely superseded by the open fit style
-Limitations - less secure, aid easier to lose
-poor acoustic seal
canal/canal lock
-suitable for mild to mod losses
-mild conductive losses to ventilate the ear
-more discreet
-may be easier to insert and remove
-good for concha deformities
- Limitations - not suitable for severe to profound losses
mould materials (non allergenic)
non allergenic option:
-very soft-> microflex, uniflex
-soft-> soft acrylic, AVC, silicone
-Hard->hard acrylic, gold plating, poly
Hard acrylic
-better for for dexterity problems
-standard mould
-easy to modify
-come in a variety of non allergenic coatings
soft acrylic
-offer a better acoustic seal
-can have a combo of hard + soft tip which offers a better seal
silicone
-durable
-non allergenic that offer excellent acoustic seal properties
venting
-intentional column of air allowing external air to ventilate the ear canal
-allows LOW freq sounds to escape so its good for patients who have good low freq HL
-vents decrease the occlusion effect
-different types of vents = acoustic vents, comfort vents, discharge vents
-larger vent= more effect/ better BUT this increases feedback
whats feedback?
feedback occurs when sound which has been amplified is fed back into the hearing aid system
tubing types
-Libby horns -increases high freq
-Reverse Libby Horns - increases low freq
-Anticondensation tubing - reduces build up of condensation
- thick tube for severe to profound because it’s wider and let’s more freq in
- thin tube for mild to mod
- the thin end is in the hearing aid for libby horn
where does tubing attach to?
attaches the hearing aid to he mould
-the smaller end of the Libby horn will be at the hearing aid, the wider end is at the horn
