Audiometric Testing and program equipment Flashcards
1
Q
Equipment for an audiometric test
A
- audiometer
- sound attenuating booth
- sound level meter with the ability to measure in octave bands
- calibration equipment
2
Q
Audiometer
A
- instruments used to measure hearing threshold
- electro acoustical instruments that provide pure tones at several frequencies and a range odd sound levels
- 500, 1000, 2000, 3000, 4000, 6000, 8000 HZ
- times are transmitted to the subject via the headphones which are calibrated to that specific audiometer and cannot be used with another machine
- 3 types
3
Q
Manual audiometer
A
- tone presentation, frequency, and sound level, and recording of the threshold is done by the technician
- models are reliable and easy to operate
4
Q
Manual audiometer advantages
A
- least expensive
- technician has control over the tone operations
- can manually fix if a person has trouble responding to the tone frequencies
5
Q
Manual audiometer disadvantage
A
- if the examiner fails to use appropriate standardized technique human error can obscure the results
- testers can develop a rhythm that is easy to predict
- testing large number of workers can be tedious
- distracted humans can easily mess up
6
Q
Microprocessor audiometers
A
- most common
- microchip is programmed for tone presentation, frequency selection, and sound level selection
- records responses based on hearing thresholds
- tone is played and worker presses a button
- if responses are inconsistent the machine will indicate the thresholds that need retesting
7
Q
Microprocessor audiometer advantages and disadvantages
A
- can also be operated manually
- can download audiometric data of workers tests onto computers
- times are consistent and eliminates technician error
- prints results
- expensive
8
Q
Computer controlled audiometer
A
- not self contained
- connected to a computer through a linking device
- software is loaded onto the computer to do the test
- the technician should not feel comfortable because the machine does all the work , results aren’t automatically valid
9
Q
Difficulties testing with audiometer
A
- patients could have tinnitus and blend into the tones so the technician needs to override the system
- machine could stop working and technition needs to enter tones manually
10
Q
Considerations when choosing an audiometer
A
- interface to a computer
- manual option
- storage
- price range
- portability
- printer capability
- fault cancelation and function checks
11
Q
Storing and handing audiometer
A
- stored in a dry cool place at room temp
- covered and protected from dust
- earphones stored with cushions facing each other
- cleaning with soap and water
- no fluid attend electrical components
- earphones not picked up by the cord
12
Q
CSA standards for a fixed facility
A
- a permanent testing area away from busy hallways and noisy equipment
13
Q
CSA standards for a mobile facility
A
- built into self-contained portable facilities that can move to a temporary location
14
Q
What does a testing area need to include
A
- a testing area with a chair , earphones, response button, required noise monitoring equipment
- a control area with an area for an audiometer and technician which includes a chair, desk, mirror , divider in which the person being tested cannot see the technician
- an advising area to discuss results and post testing procedures
15
Q
Testing difficulties in the environment
A
- when there’s lots of people to be tested, each should be isolated by separate testing booths or partitions
- can be heard in noisy environments because workers can be distracted and have difficulties concentrating
16
Q
Background noise in testing
A
- can interfere with testing and cause hearing to appear worse than it is
- must be measured before you move to a different location and records and calibration must be kept for that location
17
Q
Sound analysis
A
- is done to ensure acceptable noise levels in certain testing facilities
- can be measured using an octave band analyzer and a sound level meter
- a “ regular” sound level meter measures sound in decibels and produces one reading
- an octave band analyzer can separate the sound into different frequencies and measures the decibels at each frequency
- also a separate dial for changing the settings for each frequency so that the individual decibels reading can be made for each frequency that contributes to the overall sound
18
Q
Sound attenuating booths
A
- ensures a quiet testing environment
- make sure the sound booth is appropriate for the environment
19
Q
Supra-Aural earphones
A
- have an earphone cushion and headband
- noise reducing headphones can quiet the area
- must be calibrated to the audiometer
20
Q
Maintenance and Calibration
A
- must be calibrated using the CSA standards
- daily check and laboratory calibration
- checks help to ensure the validity of testing
21
Q
Functional daily calibration check
A
- visual check to makes sure wires, plugs, leads, and earphones du not have any damage
- ensure an dials, buttons, knobs, and lights work
- connections
-warm-up the machine and put on earphones
22
Q
Frequency listening check for daily calibration check
A
- set the audiometer at 60 dB and check tones at all frequencies in both earphones
- ensure no clicks
- make sure there is no cross talk
- make sure signal is not broken
23
Q
Intensity listening check for daily calibration
A
- set frequency at 4000Hz
- set audiometer to right ear
- present tones at each decibel level starting at 60db and ending at 0
- change to left ear and repeat step 3
- listen to the volume increases and decreases properly with no signs of noise or hums that could change tone quality
24
Q
Biological check
A
- can be completed using a device caked an bioacoustics simulator or with an individual with good stable hearing
25
Bioacoustic simulator
- an electronic instrument that responds with either an electrical signal or an illuminated light when the audiometer signal output reaches the simulators threshold for each frequency
- earphones are placed on the instrument and technician completes the test
26
Using an individual to do a biological check
- Compare current hearing threshold levels of one individual with normal/stable hearing with their previous baseline
- if it dues not differ by +/- 5 Db at all frequencies, the audiometer good to use
- if it does differ, the person with normal rearing should be compared to their previousresults
27
Laboratory or exhaustive calibration
- required a minimum of of once a year or keeping up with manufactures reccomendations
- usually done by a lab tech
- certification kept with machine
- testing should include frequency or test signals, sound pressure levels in acoustic coupler from earphones, attenuate steps, harmonic distortion, unwanted noise, mechanical deficiencies, other
28
Purpose of a biological calibration check
- record biological monitor checks of the calibration of one audiometer
- are performed every day the audiometer is used and print all information
29
Data needed about the audiometer
- manufacturer
- model number
- serial number
- last electroacoustic calibration date ( year, mouth, and day)
30
Listener instructions to maintain the audiometer
- name needed of the individual being tested
- location of test
- facility
31
Dates and data review for a biological calibration check
- date of each check
- name of examiner
- calibration check
- pass = if the check is with +/- of 5 dB in the baseline
- fail = if the check is greater than +/- 5 dB in the baseline
32
Hearing threshold levels of test frequencies in a biological test
- baseline: after listener has demonstrated test-retest reliabilities, enter hearing threshold levels of last test results in increments of 5dB
- periodic biological calibration checks: enter hearing threshold levels in increments of 5 dB
- enter remarks is anything occurs
33
Audiometric zero
- All audiometers have intensity or tone-volume control that starts at 0 dB
- does not mean that the tone presented has a sound pressure of zero
- was established while measuring a number of normal hearing subjects and determining the lowest intensity at which times could be heard
- values built into the audiometer
- allows threshold levels to be plotted in a horizontal line rather than a curve
- different from a sound pressure level of zero
- can be -5 and -10 on the attenuator dials
- occupational audiometric testing should start at 0 dB
34
Audiogram
- hearing the softest sounds a wither can hear at each frequency
- determines a workers hearing threshold much for a number of frequencies
- graphic and numeric
35
Graphic audiogram record
- pictures of hearing results
- frequencies are on the horizontal axis and are listed at the top or bottom of the graph
- intensities are on the vertical axis and are represented by horizontal lines
- left ear = x in blue
- right ear = o in red
36
Numeric cumulative records
- compares current to previous results
- shows cumulative data
- convenient for storing data
