Aural Rehab exam 2 Flashcards
Prefitting Testing includes
Estimate of hearing from Auditory brain response (ABR)
Auditory steady-state response (ASSR)
Audiologic Testing is ongoing
Estimate LDL based on thresholds
Fit with hearing aids that have wide fitting range
What are fitting considerations for the pediatric patient:
- Choose BTE over custom products
- Hearing aids should have direct audio input (DAI) and telecoils for use with FM systems
- Prescriptive methods - Desired sensational level (DSL) for children and NAL for adults
- Binaural amplification
Most reliable method for verification?
Probe microphone
Why is the probe microphone the most reliable tool for verification?
Assists audiologists in making sure the child has appropriate amount of gain for soft and average speech and that loud sounds are loud but not uncomfortable.
Post fitting procedures
- parental counseling orientation and expectation
- follow-up visits more frequent for children
- monitor hearing to determine need for adjustment of hearing aids.
- monitor earmold fit-replace earmolds once a year
How often should earmolds be replaced?
once a year
How often should hearing aids and hearing be checked?
at least once a year
Troubleshooting hearing aids, why is it important?
To maximize the patient’s hearing especially if they are in treatment.
Hearing aid troubleshooting guide includes:
- visual inspection of hearing aid while individual is wearing it
- inspection of hearing aid tubing, earmold, and battery after removal
- listening check of hearing aid with listening tube or stethescope
Cause of feedback:
- earmold or hearing aid not positioned properly in ear, sticking out
- earmold tubing is torn or there is a hole in tubing
- cerumen impaction (in external auditory canal)
- volume turned up full on
Causes of no sound from hearing aid when turned on:
-hearing aid is dead
-battery is dead
-no battery
earmold or wax guard clogged with wax
Reasons hearing aid would need to be sent in for repair:
- intermittency
- distortion
- dead hearing aid
What does it mean to have an internal problem of the hearing aid?
-microphone
-receiver
amplifier
What is the primary application for FM systems?
For children in the classroom (however adults are also able to take advantage of the FM systems)
What are the four regular classroom acoustics like?
-children talking, coughing
-squeaky chairs
fan motors cycling on and off
-feet shuffling
What do the regular classroom acoustics mean for a hearing-impaired child wearing personal hearing aids?
- personal hearing aids amplify background noise
- Affecting speech perception (speech intelligibility)
- The further the hearing impaired child is from the teacher the softer the speech signal becomes
- lost opportunities for learning through the auditory channel.
What are the 3 basic conditions that negatively affect all aspects of listening for a hearing-impaired child who wears conventional hearing aids?
- Background noise
- distance from the speaker/teacher
- reverberation
____ __ ______ ratio is an important factor- it is defined as the relationship of the intensity of the signal of interest to that of background noise
signal to noise
The ____ the sound to noise ratio is the worse the listening condition
poorer
An example of sound to noise ratio: +10 dB S/N ration mean:
speech is 10 dB greater than the noise
-10 dB S/N ratio means:
noise is 10 dB greater than speech
+0 dB S/N ratio means:
speech and noise are at the same intensity level
Normal hearing children can cope with a ____ S/N ratio
+5dB
Hearing impaired children with hearing aids require a ____ to ____ dB S/N ratio
+15
20
In order for a teacher to achieve a +20 dB S/N ratio she would have to maintain a distance of ___ inches from the child’s______ and ______
9
hearing, microphone
As distance _____ between the teacher/speaker and the hearing impaired child, there is a _______ in the intensity of the teacher’s voice making it more difficult for the child to hear and understand speech.
increases, decrease
_______ ________ may help to avoid increasing the distance from the speaker/teacher
preferential seating
- echo affect of sounds reflecting off hard walls
- effects intelligibility of speech
- architects now taking this into consideration when building new schools
reverberation
What advantages does the Fm system provide:
- achieve an optimal s/n ratio without having the teacher 9 inches from the microphone
- the distance between the teacher and child remains constant
- eliminates problem with room reverberation
Wireless system (no connection between the speaker and listener)
FM system
FM
Frequency modulated
Federal Communications Commission (FCC) has authorized use of _______ MHz bandwidth also known as auditory assistance band primarily used for assisting hearing-impaired persons in their communication needs.
72-76
How does the FM system work?
- FM signal transmits sound via a radio frequency carrier wave at distance of 50 to 150 feet depending on the system. Must have a transmitter and receiver
- sound enters the microphone and acoustical energy is converted into an electrical signal and sent to the transmitter.
- signal is then sent through a frequency modulated carrier wave to the FM receiver where it is amplified
- FM receiver demodulates the signal changing it back to acoustical signal and delivers it to the listener’s ears. Excellent sound quality
What are the basic components of the FM System
- transmitter/microphone
- receiver
- methods of sound pickup from FM receiver
FM component that is worn by the speaker/teacher on the body clipped to a belt or hanging by cord
transmitter
component of FM system that is connected to the transmitter, plugged into mic/ant jack placed about 4-6 inches below the child
microphone
component of FM system worn by listener or child
receiver
Methods of sound pickup from FM receiver-ways to configure:
- FM receiver is attached to a personal hearing aids
- FM receiver is built into the hearing aid (phonak link)
- FM receiver is used with earbuds
- FM receiver is used with a neckloop and personal ITE or BTE
- FM receiver is used with a DAI cord and audio shoe connected to their personal BTE
- FM receiver is worn with a BTE microphone
What are the three settings the receiver has?
- FM
- FM/HA
- HA
FM
hear only the teacher/speaker voice
FM/HA
hear the teacher and environmental sounds
HA
hear environmental sounds
Jack connects to DVD player or TV and located on receiver and transmitter. charge unit here
auxiliary
FM system placed in over night for re-charging nickel hydride batteries
charger
What are advantages of the FM system?
- Wireless transmission
- high-quality signal that provides access to intelligible speech
- flexible system
- choose from several types of receivers
- can be used indoors and outdoors
- no electromagnetic interference
- receiver does not have to be in line with the transmitter
- can be used in adjacent rooms without interference
- portable
What are the disadvantages of an FM system?
- 72-76MHz is allotted frequency band that has the potential of outside interference from fire call boxes and paging systems as well as radio stations
- it two transmitters are on the same frequency and are used in close proximity, there is potential for interference
- expensive and need care and maintenance, rechargeable batteries, repair costs are relatively high.
What are the populations that can be served by FM systems?
- minimal hearing loss
- mild hearing loss
- unilateral hearing loss
- auditory processing disorder-difficulty understanding speech in presence of background noise
- phonological disorders
Easy listener by phonic ear:
low gain, low output, wireless transmitter and reciever
microear by phonak
low gain, low output, wireless BTE receiver. same population as other FM systems. requires a transmitter: cannot change frequency
isense by phonak
behind the ear, also low gain receiver
ARC by phonak
low gain, low output, wireless receiver
The soundfield system is used for an individual or group?
group use
What population does the soundfield system use?
same as easy listener
What kind of system does the soudnfield system use?
Front row
What are the advantages of the soundfield system?
same as with other FM system but in this case the whole classroom benefits from the system
+10 dB signal to noise ratio-held constant regardless of where the teacher stands
What are the disadvantages of the soundfield system?
- not portable
- not strong enough to provide enough benefit for a child with severe or profound HL
- poor acoustics of the room may create reverberation
- teacher must be receptive to its use otherwise benefit is diminished
- wireless but not based on FM techonology
The induction loop system eliminates ________
reverberation