Audiology 2

unknown etiology

% of babies every year with a major birth defect

Approximately ___ in ____ people carry a recessive gene for hearing loss in the general population.

% of children born with SNHL have two biological parents with normal hearing

% of the offspring of deaf biological parents have normal hearing

% of genetic causes of hearing loss

% of SNHL caused by syndromes

most common syndromes involving SNHL

Contributes to a lot of biochemistry within cochlea
Common cause of genetic hearing loss

Popular philosophy in late 1800/ early 1900 that
undesirable traits can be eliminated and desirable traits made more prominent through selective breeding of humans

Approximately 95% of prenatal babies diagnosed
with down syndrome in the U.S. are now “terminated”

Anything that can assault the body

A child is very susceptible from 3-9 weeks of gestational age (after conception) because of the formation of the organs at that time

environmental teratogens

Common virus that usually causes a small, harmless infection, except prenatally
1 in 25 women will contract it while pregnant; 33% will pass it on to their baby
Women who contract it before pregnancy only have a 1% chance of passing on the virus
No vaccine or treatment 
Prevention: good handwashing, esp. after exposure to small children and the sick

A screening test’s accuracy in correctly identifying those with the condition (alone it also identifies those without condition)

A screening test’s accuracy in correctly identifying those without the condition

% of children with some sort of hearing impairment have to repeat a grade

People who adminster hearing screening

-detects neural response of brain
-Waves labeled I-VII     
-Each wave represents a synapse through the brainstem     
-Looking for presence or absence of wave V at the screening level
-Only I, III, and V comes through for babies

-Puts a sound in the ear with a probe and elicits an acoustic response in the ear
-produced by outer hair cells
-detects whether outer hair cells are working or not

how much hearing is left without any sensory device

pediatric CI team

Teaching listening without lipreading

Use hand shapes and hand positions accompanied by aural
To assist with sounds that are hard to see
Not sign language

Don’t cover your mouth, includes lipreading skills

Use anything and everything to communicate 

Reveals they have a hearing loss but they really don’t

Reveals they have a hearing loss and they really do

Reveals they don’t have a hearing loss but they really do

Reveals that they do not have a hearing loss and they really don’t

LSLS

UNHS

OAE

ABR

3 Key Components of Early Hearing Detection and
Intervention Programs

Unilateral or bilateral hearing loss (sensorineural or conductive) of greater than 20 dBHL in the frequencies of 500-4000 Hz

develops speech and lan­guage skills primarily through the auditory mode and employs (or is capable of employing) a primarily auditory‑verbal system of communication. While many of these children may be depend­ent upon visual cues for interpersonal communication, vision is still a secondary channel compared to audition.
more related to typical hearing children, but not treated that way, treated as high level deaf child

any person whose development of communication skills occurred primarily through the visual channel and whose current mode of communication is primarily visually based.

5 communication options

technology used to monitor the reliability of the intracochlear
electrodes after being surgically implanted into the cochlea.  It is used to check that the internal components of a cochlear implant have not malfunctioned

-Adjusting the level of electrical impulses
-Audiologist sets minimal and maximal current for each electrode (unique and dynamic)
-Initially  at 3-5 weeks post-surgery, then in 2 weeks, months (for 6 months), and then annually
-T-level (threshold), C-level (comfort)

6 criteria for pediatric implant

5 cochlear implant components

Receives signal from external components

Implanted just below the skull within the
temporal bone

Part that’s implanted
  
Between 18 and 24 electrodes

Inserted within the cochlear

Want them to be as close to the nerve fibers
as possible

Body worn or Head worn

Mini computer

 takes sound from microphone and converts it into the key features that the brain needs to comprehend the sounds they are listening to.  The code is going to the auditory nerve.  The electrodes are representing the hair cells.  The pattern that is coded comes through the electrodes and sent to the auditory nerve.

A magnet and a this, signal this by radio frequency

Magnet to keep it on the head

Receives coded signal

CI manufacturers

3 components of hearing aid

part of HA that picks up sound from the environment and converts it into an electrical signal, which it sends to the amplifier.

part of HA that increases the volume of the sound and sends it to the receiver.

part of HA that changes the electrical signal back into sound and sends it into the ear. Then those impulses are sent to the brain.

S/N

SN

_____ S/N ratio adversely affects speech recognition

Typicainsurance coverage of hearing aids for children 

70% of speech between 500-2000 Hz

Reason why PTA is 500,100 and 2000 Hz

4 components of an FM system

Before the sound is sent to the receiver, it transmitter ensures that no part of the sound signal is greater than 70dB SPL. This is achieved through compression of the incoming
sound waves.
The sound is sent from it to the receiver that is attached to the child's hearing aids, by radio frequency waves.

converts the radio waves back to electrical energy which is sent to the hearing aid for amplification.

3 types of genetic transmission

20% of genetic etiologies
family history (each generation)
50% chance each conception

80% of genetic etiologies
No family history
25% chance each conception

<1% of genetic etiologies
Son has 50% chance of inheriting gene from
mother each conception
Daughters unaffected