Audiology - Testing Flashcards
What information should be included when taking a case history regarding hearing?
Background details (for child inc pre- and peri-natal)
Family history of hearing
Hearing difficulties experienced
Audiological history
Educational history
Occupational history
What are the two classifications of hearing tests?
Subjective or objective
What is meant by a subjective hearing test?
A test which measures perception of an auditory stimulus
What is meant by an objective hearing test?
A direct hearing test which measures physiological response to auditory stimuli
How can you ensure the reliability of hearing tests?
Follow the British Society of Audiology recommendations, use specialised calibrated equipment, minimise background noise
What is the most frequent way of representing human hearing levels?
A pure tone audiogram
What does a pure tone audiogram plot?
Intensity vs frequency
What is ‘Audiometry’?
The testing of a person’s ability to hear various sound frequencies
What are the two purposes of hearing tests?
To SCREEN for a hearing problem and to DIAGNOSE (describe) the hearing impairment
What are the aims of hearing test screeners?
To identify hearing impairment quickly, cheaply and accurately
What are the aims of a diagnostic hearing test?
To describe the person’s hearing impairment and to create an audiological profile
Name some of the subjective hearing tests
Pure tone audiometry (air conduction / bone conduction), Toy tests (behavioural tests for children), Speech Audiometry
Name some of the objective procedures for hearing loss
Tympanograms (middle ear measurements), Auditory brainstem response, Oto-acoustic emissions
In an audiogram where is 0?
At the top (the graph is inverted!)
What does dbHL stand for?
Decibel Hearing Loss
Which axis on the audiogram is labelled with dbHL?
Y axis (intensity of sound)
What is measured on the X axis of the audiogram?
Frequency of sound
What is the unit used to measure frequency on the audiogram?
kHZ
What is meant by threshold of hearing?
The quietest audible sounds that can be heard
What are the normal thresholds on an audiogram?
minus 10dbHL to plus 15dbHL
What is meant by the dynamic range?
The difference between the quietest sounds and the loudest sounds we can hear
What are the two procedures for pure tone testing?
Air conduction and bone conduction
What is an air conduction test?
When the stimulus travels through the outer and middle ear to reach the cochlea
Which hearing system does the air conduction procedure test?
The peripheral hearing system
What is a bone conduction test?
When the stimulus is given to the cochlea by-passing the outer and middle ear
How is the right ear represented for an air conduction test on the audiogram?
0
How is the left ear represented for a air conduction test on the audiogram?
x
What does air conduction testing involve?
The client listens to stimuli presented to each ear separately. Client indicates when increasingly quiet sounds are heard
What does bone conduction testing involve?
The simuli are bone conducted pure tones presented to each ear separately via a bone vibrator held to the mastoid processes
What will a bone conduction test show?
Which is the better ear
How can you attempt to ensure a response from each cochlea in a bone conduction test?
By keeping the non-test ear busy by masking the test-stimuli
How do you mask the test-stimuli in a bone conduction test?
Present a narrow band (500 - 1500 Hz) noise to the non-test ear
How is the right ear represented for a bone conduction test on the audiogram?
[
How is the left ear represented for a bone conduction test on the audiogram?
]
What is an unmasked bone conduction test represented on the audiogram?
With a triangle
What is an unmasked bone conduction test?
When vibrations are put on the client’s forehead. This results in the better ear responding despite both ears responding
Why can’t you deliver high intensities in a bone conduction test?
Because the client will feel the vibrations rather than responding to to the sounds
What is the usual upper limit for test stimuli?
70dbHL
Why might someone with severe profound hearing loss not be able to have a bone conduction test?
Because it would require stimuli above the upper test limit (70dBHL)
What will a typical audiogram of an impaired ear show?
A sloping curve with better hearing in low frequencies and worse hearing in high frequencies
What type of hearing loss does middle ear disease result in?
Conductive
If someone is suffering from conductive hearing loss but not sensori-neural hearing loss, what will their audiogram show?
An air bone gap
What will the audiogram characteristics be for someone suffering from sensori-neural hearing loss?
Both bone and air conduction results will be abnormal
Why is air conduction affected in sensori-neural hearing loss?
Because the cochlea is damaged
What is mixed hearing loss?
Sensori-neual and conductive hearing loss
What will the audiogram characteristics be for someone suffering from mixed hearing loss?
Both bone and air conduction tests will be abnormal and there will be an air bone gap
What is bilateral hearing loss?
Hearing loss in both ears (can be asymetrical or symetrical)
What is unilateral hearing loss?
Hearing loss in only one ear
What is the pure tone average for mild hearing loss?
20 - 39 dBHL
What is the pure tone average for moderate hearing loss?
40 - 69 dBHL
What is the pure tone average for severe hearing loss?
70 - 94 dBHL
What is the pure tone average for profound hearing loss?
Greater than 94 dBHL
What is meant by ‘congential’ hearing loss?
Hearing loss that is present at birth or up to 12-15 months (before language develops)
What is meant by ‘acquired’ hearing loss?
Hearing loss that develops from 15 months (post-language)
