Lecture 5.2 Flashcards
When are bone conduction hearing aids used?
for conductive or mixed hearing loss
when middle ear issue requires direct stimulation of the cochlea of the skull
or for those who can’t wear air conduction hearing devices
- anatomical limitations or chronic middle ear problems
surgery not possible until at least age 5
What are the types of bone conduction HA?
direct (surgically applied)
- percutaneous - vibrations directly to bone
- active transcutaneous - across skin; external processor stimulates transducer under skin
passive
- non-magnetic - headband/adhesive (children who are not yet candidates for surgery can use)
- passive transcutaneous - external transducer across skin to implanted magnet
What is microtia?
underdeveloped pinna
What is anotia?
pinna completely underdeveloped or absent
What is atresia?
absence or abnormal narrowing of the ear canal
What is the incidence and common features of pediatrics needing bone conduction hearing aids?
1-18 / 10,000 births
features: male, unilateral (RIGHT), intact cochlear function, First Nation/Hispanic/Asian
What is the general etiology of needing bone conduction hearing aids?
genetic and environmental
What are 2 general surgical solutions?
cosmetic - improve external ear appearance, unlikely to resolve conductive loss
hearing - surgical or non-surgical bone conduction hearing device offer best solution for providing speech access
Who are candidates for non-surgical transcutaneous BCHDs?
2 months+ and display one of:
- conductive or mixed hearing loss
- lack of benefit from air conduction hearing aids
- contraindications for surgical placement
What are the qualifications for surgical eligibility?
sufficient skull thickness and bone quality
currently recommended no earlier than 5 years old
How do the soft headband or adhesive options work?
delivers sound via vibrations across the skin to the skull
no surgery required
good for children with conductive or mixed hearing loss who don’t have properly former outer ear or ear canal to accommodate BTE aid
What is CROS/biCROS?
contralateral signal routing
wireless transmission from poorer ear to better ear
What are the benefits of CROS/biCROS?
can improve sentence recognition and story comprehension compared to other conditions
- most apparent benefit when signal on better side
eliminate head shadow effects
effective in quiet situations
What are the adverse effects of CROS/biCROS?
may have adverse effects in complex listening situations
noise will also be routed to better ear (previously attenuated due to head-shadow effect)
doesn’t facilitate use of binaural hearing so sound localization unlikely to improve
What are the candidacy characteristics for CROS?
current pediatric amplification guidelines and protocols align
young children have challenge controlling dynamic nature of sound in environment, not candidates in most programs
avoid occluding normal hearingI (prevents occlusion)
