Aural Rehabilitation Exam I Flashcards
Activity Limitations
This is a loss of activity that occurs at the level of the person. Examples could be avoiding social gatherings because of communication issues, or missing auditory cues such as the doorbell.
Participation Restrictions
This is a loss of participation that occurs at the level of society. This refers to changes in one’s entire lifestyle. Examples of this could be having trouble following what’s going on in class or work.
Impairment
What is not properly functioning? In the ear, this could be the cochlea or middle/outer ear problems. This could also be considered a general hearing impairment which refers to the complete or partial loss of hearing in one or both ears.
Air Conduction Audiogram Symbols
Right Ear- O
Left Ear- X
Bone Conduction Audiogram Symbols
Right- Unmasked: < Masked: [
Left- Unmasked: > Masked: ]
Audiogram Symbols for Hearing Aids/Cochlear Implants
A- Aided thresholds (hearing aid)
AR- Right ear-aided threshold
AL- Left ear-aided threshold
C- Threshold with Cochlear Implant
SRT
This test utilizes spondee words (bisyllabic words) to figure out what’s the softest level in which a person can repeat 50% of the words.
WRS
This test is focused on the percentage correct a person can get when repeating words heard at a comfortable level. Uses sentences or phrases.
Types of testing
-Audition only (No visual cues)
-Vision Only (Just speech reading)
-Audition and vision (audio and speech reading)
Test Considerations
- Format of response
- Test Presentation
-Type of stimulus
-Noise Condition
Hearing Aid Components
Parts of a hearing aid include:
-Microphone: Converts signal from acoustic to electrical
-Amplifier: Amplifies/increases signal
-Reciever: Converts signal from electrical to acoustic and delivers signal to cochlea
-Batteries: Give power
Microphone
The microphone consists of a diaphragm and a backplate, and voltage occurs between these two pieces which is created from diaphragm movement. This voltage signal is then passed to the amplifier.
Types of Microphones
There are three types of microphones including:
Directional: These microphones pick up on sound in front of the user, improve signal-to-noise ratios, and is good for listening around noise.
Omi-Directional: These microphones pick up on sounds in all directions, it’s often used in quiet listening situations.
Automatic Directional: Omni-directional change
Amplifier
This part of a hearing aid amplifies a signal. A gain (or amplification amount) can be measured by doing the output (loud) minus input (soft).
Receiver
The receiver converts a signal back into acoustic energy, and it can be referred to as a small loudspeaker.
Hearing Aid Features
Multiple Channels- The signal is processed into frequency bands with some bands having more gains than others.
Programmability- The computer controls hearing aid parameters including gain and compression.
Noise Reduction- The difference in sound pressure level between noice measured in two different locations.
Feedback Cancellation- Feauture that reduces squeling sounds produced by hearing aids when the microphone reamplifies an amplified sound.
Additional Hearing Aid Features
-Volume wheel on-off switch
-Opening/closing battery door control on-off
-Audio input (Ex: Plug into tv)
-Telecoil: Picks up telephone signals
-Volume control: Adjust level of amplification
-Remote Control: Program memories and change volume
Types of Hearing Aids
-Behind the Ear
-In The Ear
-In The Canal
-Completely In The Canal
-Body Hearing Aid
-Lyric
Behind the Ear
These are bannana-shaped with all the electronics housed behind the ear with an ear mold delivering sound from the reciever to the ear canal. They are more relaible and provide better sound quality than smaller hearing aids. This is used for more severe hearing loss cases and recommended for children. Serves mild to profound hearing losses.
In the Ear
This serves people with mild to severe hearing losses. This fits within the inner ear without visble tubes and wires.
In the Canal
This can serve mild to moderately severe hearing losses. Less visible easy to maintain. It is less powerful and presents difficulties in relation to insertion, battery, and use of volume.
Completely in the Canal
Serves mild to moderate hearing losses.This is one of the least visible and requires less volume. Less feedback when on the telephone, better amplification of high frequencies, and does not serve some ear canal shapes.
Body Hearing Aid
A case attached to a persons clothing containing a large microphone, amplifer, and power supply. The receiver attaches to an individuals ear and recieves power through wires connected to the amplifier. This is the most powerful hearing aids and often used by people with profound hearing loss or children.
Output limiting
This is the process in which the maximum power output of a hearing aid is limited. This can be done through peak clipping or compression.
Peak Clipping
Clips signal peaks at saturation level before they become painfully loud. Can cause loss of sound quality or distortion.
Compression
This limits maximum power output without distortion and provides sounds within a dynamic range. The knee point is the intensity level at which compression is activated. Attack time is the amount of time needed to activate compression and release time is the time needed to increase gain after a signal decreases.
Digital vs. Analog Hearing Aids
Analog: All of the types of hearing aids aforementioned, inexpensive, non-programable, and converts sound into electrical signals.
Digital: Newest form of hearing aid, a computer chip separates the unwanted sound from speech, and automatically adapts to changes in the listening enviorment.
Dynamic Range
Soft sounds are soft. Medium sounds are normal. Loud sounds are loud.
Uncomfortable loudness level (UCL)- Speech Recognition Threshold (SRT)= Dynamic Range
Azimuth
Position of a loudspeaker to a listener. 0 degrees azimuth would be in front of a listeners face.
