Pure Tone Audiometry

Front 1

What five factors are important for a successful pure tone audiiometric result?

Back 1

*the patient
*the environment
*test equipment
*the examiner
*test procedure

Front 2

What is it important to consider about the patient one is planning to test?

Back 2

One needs to have an assessment of the patient and their capabilities and some opinion as to what type patient we're dealing with and what their capabilities are.

Front 3

What type of environment is preferable for audiometric evaluation?

Back 3

A sound treated room, with patient in double walled room to attenuate as much external noise as possible.

Front 4

What should be your main concern with the testing equipment?

Back 4

The calibration of the equipment.

Front 5

What is important to know about the examiner performing the audiometric testing?

Back 5

The examiner needs to be properly trained and knows proper protocol, and how to consider the factors, such as patient and environment and etc.

Front 6

Why is it important to follow a specific test procedure?

Back 6

Procedures have been researched thoroughly, and continually refined over time to ensure correct results.

Front 7

What is the testing equipment called used to assess hearing?

Back 7

Audiometer

Front 8

What do the two large dials on an audiometer control?

Back 8

1. Intensity of stimulus
2. Frequency of stimulus

Front 9

Why must the signal be atteuated on the audiometer?

Back 9

Tone is sent through at maximum intensity. Must be squelched or attentuated to appropriate level.

Front 10

If stimulus is delivered via earphones, it is delivered via ____ ________.

Back 10

Air Conduction

Front 11

Using the professors picture, can you label the different parts.

Back 11

Parts: attenuator, masking dial, where stimulus sent indicator, type of tone indicator, frequency dial, intensity dial

Front 12

If stimulus sent via bone oscillator, it is sent via ____ __________.

Back 12

Bone conduction

Front 13

Why are there lower intensity limits for bone conduction than for air conduction?

Back 13

It takes more power to drive the bone oscillator than wth air conduction outputs. The intense power can cause harmonic distortions causing the actual intensity to not match what you're trying to send (1500, vs. 1000 Hz for example). Also, tactile sensation so strong patient may think they hear, vs feel it.

Front 14

Where should the center of earphones (with the grid) be placed

Back 14

Directly over the ear canal

Front 15

Earphones are called _____ _____ earphones and why is this important?

Back 15

Supra aural. This means that they must go over the top of the ear and cover most of the auricle.

Front 16

When earphones are color coded, what colors dilineate left from right pieces.

Back 16

Red is right and blue is left.

Front 17

Where can the bone oscillator be placed?

Back 17

It can be placed on the left OR right side, OR forehead OR any other place on skull.

Front 18

What are the Hz frequencies we test?

Back 18

125, 250, 500, 1000, 2000, 4000 and 8000

Front 19

When testing a patient, remember that their right side is on your _____ and their left side is on your _____.

Back 19

left, right

Front 20

Testing procedure protocol requires that you begin testing at what Hz?

Back 20

1000 Hz

Front 21

Why are 3000 Hz and 6000 Hz sometimes on an audiogram?

Back 21

Sometimes an audiologist wants to know the threshold at these half octaves.

Front 22

In testing the dB increments are in ____.

Back 22

Tens (ex: 10 db, 20, db, 30 db and etc.)

Front 23

What is the maximum intensity level we would ever test at?

Back 23

110 dB

Front 24

What symbol and colors would you use for marking the results for the right ear?

Back 24

round and red (Note r and r for right)

Front 25

What symbol and colors would you use for marking the results for the left ear?

Back 25

Blue and X

Front 26

Right ear bone conduction markings are:

Back 26

< (it's open to your right)

Front 27

Left ear bone conduction markings are:

Back 27

> (it's open to your left)

Front 28

Triangle icon means what?

Back 28

Left ear masked when sound delivered to right. Note( r in triangle, to go with r in round and red for right ear markings!)

Front 29

Box icon means what?

Back 29

Right ear masked when sound delivered to left.

Front 30

Define threshold

Back 30

The level at which a stimulus,such as a pure tone, is barely perceptible. Usually clinical criteria demand that the level be just high enough for the subject to be aware of the sound at least 50 percent of the time it is presented.

Front 31

What kind of instructions should be given a patient before beginning.

Back 31

Tell them what to expect, and stay away from jargon. Tell them therre will be different tones at different loudness levels, NOT different frequencies at different intensity. Give them instructions on how to indicate when they hear the tone, and ask which ear is their better ear.

Front 32

What information do most clinics follow that came from research published in 1959 by Carhart and Jerger?

Back 32

Information regarding how to go about finding the threshold of a patient.

Front 33

Carhart and Jergers technique is also known as the _________ ___________.

Back 33

Ascending technique.

Front 34

Describe the ascending technique of Carhart and Jerger.

Back 34

Start at 1000, then test 2000, 4000, 8000. Retest 1000, then test 500, 250, 125.

Front 35

Why do we retest at 1000 Hz in ascending technique?

Back 35

1000 Hz is:

Front 36

What is acceptable retest results at 1000 Hz.

Back 36

It is acceptable to have results within 5 dB. If it's 10 dB or more, we need to figure out why.

Front 37

How long should we present a tone to a patient?

Back 37

One to two seconds.

Front 38

At what decibel level should we present our first tone at 1000 Hz?

Back 38

30 dB

Front 39

Explain gross threshold search.

Back 39

If there is no response at the 1st presentation at 30 dB, raise the tone to 50dB HL. If there is no response on up into the higher intensities, continue raising the tone in 10 dB steps until a response is obtained.
If there is a response at the 1st
presentation at 30 dB, lower the tone in 10 dB steps until there is no response from the patient.

Front 40

Describe fine threshold search.

Back 40

DOWN 10 dB - UP 5 dB

Front 41

How do we find the pure tone average.

Front 42

What frequency range is the speech frequency?

Back 42

500 Hz to 2000 Hz

Front 43

At what PTA range would you say there is no hearing loss?

Back 43

-10 to 15 dB

Front 44

At what PTA range would you say there is a slight hearing loss?

Back 44

16 to 25 dB

Front 45

At what PTA range would you say there is a mild hearing loss?

Back 45

26 - 40 dB

Front 46

At what PTA range would you say there is a moderate hearing loss?

Back 46

41-55 dB

Front 47

At what PTA range would you say there is a moderately severe hearing loss?

Back 47

56-70 dB

Front 48

At what PTA range would you say there is a severe hearing loss?

Back 48

71-90 db

Front 49

At what PTA range would you say there is a profound hearing loss?

Back 49

91 dB +

Front 50

Are testing procedures the same for BC as for AC? Why or why not?

Back 50

They are essentially the same. The difference is that you've already have threshold via AC, which will inform where to start testing for BC conduction.

Front 51

Why would you have a bone oscillator and a supra aural headphone on the patient at the same time?

Back 51

You would have both, so that you could mask the ear you do not want to test.

Front 52

Explain distortional bone conduction.

Back 52

As we distort the bone and in a moment rarefy and compress it;that movement causes an up and down motion on the basilar membrane which is interpreted as sound in the same fashion as when they're stimulated by air conduction.

Front 53

A ________ contribution to the total bone conduction experience is distortional bone conduction.

Back 53

Main

Front 54

A ________ contributor to the total bone conduction experience is osseous-tympanic.

Back 54

Minor

Front 55

Explain osseous-tympanic conduction.

Back 55

The bone conduction causes vibration of the bones around the middle ear. This changes pressure in the ear canal creating air conduction (via bone conduction) that now comes in through tympanic membrane and increases perception of sound.

Front 56

Explain inertia bone conduction.

Back 56

As the ear is stimulated by bone conduction, the ossicular chain suspended in the middle ear lags behind the stimulation by bone conduction. Therefore, the lagging behind will cause the stapes to move and give compressions and rarefactions at the oval window.

Front 57

Name the three contributors to bone conduction experience.

Back 57

Distortional bone conduction, osseous-tympanic bone conduction, and inertia bone conduction.

Front 58

What is the speech banana on an audiogram?

Back 58

The area where the speech energy is found at converstional levels.

Front 59

What would you expect if a person's hearing level drops below the speech banana?

Back 59

They would be having problems with speech perception.

Front 60

Which ear would you test first?

Back 60

You would start with the patient's better ear. If they don't know, then the right ear is traditionally the one to start with.

Front 61

What two frequencies would you most likely NOT see bone conduction testing on?

Back 61

125 Hz and 8000 Hz

Front 62

If there is an arrow pointing downward on the audiogram, what does it mean?

Back 62

It means that we tested to the limit of our audiometer and were not able to get a response from the patient.

Front 63

If you have a circle denoting test results showing a hearing loss, what other items should you be considering (two other circles with the three being a triangle)

Back 63

Your other two circles should be anatomy and disorders. All three circles are interrelated.

Front 64

Why would an audiogram of a person with normal air conduction hearing not be tested by bone conduction?

Back 64

It would be foolish to test by bone conduction. If you get normal hearing, threre is normal bone conduction.as well.

Front 65

What is an air bone gap?

Back 65

A gap between air conduction and bone conduction.

Front 66

ABG is ___ ______ _____.

Back 66

Air bone gap

Front 67

PTA is an acronym for what?

Back 67

Pure tone average

Front 68

What type of hearing does this person have?

Back 68

Normal hearing

Front 69

What type of hearing does this person have?

Back 69

Bilateral conductive loss

Front 70

What type of hearing does this person have?

Back 70

Bilateral mixed hearing loss

Front 71

What type of hearing does this person have?

Back 71

Bilateral sensorineural loss

Front 72

What type of hearing does this person have?

Back 72

Unilateral conductive loss

Front 73

What type of hearing does this person have?

Back 73

Unilateral sensorineural loss

Front 74

Explain why the top portion is listed as a sensorial neural loss (vs. the bottom portion)

Back 74

With the bone gap made up with via bone oscillation, you are seeing what the cochlea is truly able to hear. This makes the bottom portion reflective of what the bone conduction adds to the mix.

Front 75

Explain the abbreviations TE and NTE

Back 75

TE = the ear being tested
NTE = the ear that is the ear that is not being tested.

Front 76

Explain the concept of cross hearing.

Back 76

This is when during audiometric testing the sound being presented to the poorer ear, travels and is heard by the better ear.

Front 77

If when presenting the stimulus (sounds) via air conduction (AC); if there is cross hearing then:

Back 77

Stimulus can be heard via both AC and BC going from the TE to the NTE

Front 78

If when presenting the stimulus (sounds) via bone conduction (BE); if there is cross hearing then:

Back 78

stimulus will travel via BC from the TE to the NTE

Front 79

Using everyday words, what does interaural attenuation mean?

Back 79

Between the ear attenuation. Here attenuation means the diminishing or dampening of sound.

Front 80

Explain interaural attenuation.

Back 80

As the stimulus travels from one side of the head to the other, some energy is lost in transmission. So the head's kind of a barrier. This loss is called interaural attenuation, sometimes abbreviated IA.

Front 81

IA factor will change with _________ and ____________.

Back 81

Different frequencies
Vary with different people

Front 82

The IA for AC is:

Back 82

40 dB

Front 83

The IA for BC is:

Back 83

0 dB

Front 84

What are we really saying when we talk about the IA being 40 dB by AC

Back 84

We know our studies show sound crosses from one side of the head to the other at around fifty dB or so. But we will assume if there is a difference between the ears, in air conduction, we will assume or be wary of the possibility of cross hearing when that difference is forty dB.

Front 85

Why is IA for BC at 0 dB?

Back 85

Because with BC, the head has no attenuation.

Front 86

Explain what this formula really means.
AC (TE) – IA ≥ BC (NTE)

Back 86

After we obtain threshold for both ears, we go back and and look at our threshold we've obtained. We subtract forty dB of attenuation from that threshold value. If the result is equal to or greater than the bone conduction in the non test ear, then we have to suspect and take appropriate measures for dealing with cross hearing.

Front 87

When should we suspect cross hearing in AC? (if not using formula)

Back 87

See if there a more than forty dB difference between the bone conduction in the TE and bone conduction NTE ear? If the answer is yes. We have to be suspicious of cross hearing.

Front 88

When should we suspect cross hearing in BC?

Back 88

Cross hearing can be suspected whenever there is an air bone gap in the test ear greater than ten dB.

Front 89

What's the formula for suspicion of cross hearing in BC?

Back 89

ABG (TE) > 10 dB

Front 90

What did the professor expect us to know about central masking?

Front 91

What is white noise?

Back 91

When you see all the frequencies represented equally.

Front 92

What is pink noise?

Back 92

White noise, that is filtered, whereby each octaves has been reduced or attenuated by three dB. If mapped out, you see the stair step at the top with each stair showing a reduction by three dB.

Front 93

What is the long term speech spectrum?

Back 93

This is where white noise is filtered by taking frequencies from one thousand Hz below, down in that direction, and have reducing the intensity three dB per octave. Then in the higher frequencies, attenuating the intensity of the white noise or filtering it off at twelve dB per octave

Front 94

Recording noise from a cafeteria over a long period of time would result in noise that looks like:
a: white noise
b: pink noise
c: long term speech spectrum

Back 94

Long term speech spectrum. Most energy here is between 500 and 2000 cycles per seconds (Hz).

Front 95

When is long term speech spectrum excellent for masking?

Back 95

When you are using speech as the stimulus in the test ear.

Front 96

What is narrow band noise (NBN)?

Back 96

The white noise is taken and filtered to noises around a central frequency. This is done for each frequency you're testing.

Front 97

When is NBN or narrow band noise the best masking to use?

Back 97

When you are are doing pure tone audiometry testing.

Front 98

What is sawtooth noise?

Back 98

A non aperiodic sound. It consists of a fundamental frequency, usually 60 Hz since that's the frequency from the alternating current wall plug in a series of harmonics.

Front 99

When would you find sawtooth noise used as the masking in an audiometer?

Back 99

In cheap audiometers. It is cheap to make and is questionable as a masker. It's generally not used much anymore.

Front 100

We calibrate our instrument in masking so that ________________________.

Back 100

it will deliver a masking noise at an effective level for a given stimulus tone. In other words, if we want to present in the test ear a stimulus tone of a given intensity, we would like to deliver a corresponding masking tone in the nontest ear that would assure us the test tone would not cross the head.

Front 101

How do you calibrate an effective tone for masking?

Back 101

1.Present a tone to one ear by air conduction at 1000 Hz at 30 dB. Interrupt the stimulus tone to avoid fatigue
2.Present a noise (preferably, a narrow band) to the same ear
3.Raise the level of the noise in 5 dB steps until the 30 dB tone is no longer audible but can be heard at 35 dB. Recheck several times
4. Take a median value of the masking level dial setting at which the 30 dB tone was masked. This represents 30 dB EM. Five to 10 dB may be added as a safety factor
for accuracy
5. Mark the audiometer’s masking level dial 30 dB below the average of 30 dB EM
(plus the safety factor) as 0 dB EM – OR post a correction chart showing the number of dB that must be added to 0 dB HL to reach the 0 dB EM level.
6. Repeat this procedure for all audiometric Hz.

Front 102

Testing procedure when masking.

Back 102

1. Increase masking until the tone not heard.
2. Increase intensity of tone at same masking level. If tone heard, increase mask. If tone not heard, increase intensity.
3. Repeat number 2 until you get three "yes" answers at higher masking levels. This will be your EM or effective masking level.

Front 103

Testing procedure when masking.

Back 103

1. Increase masking until the tone not heard.
2. Increase intensity of tone at same masking level. If tone heard, increase mask. If tone not heard, increase intensity.
3. Repeat number 2 until you get three "yes" answers at higher masking levels. This will be your EM or effective masking level.

Front 104

What does this picture represent or show?

Back 104

Under masking, the effective masking plateau and over masking.

Front 105

When discussing various audiograms at the end of lecture for week 8, the instructor asked questions when looking at the audiograms to determine whether to mask. What were they?

Back 105

1. Does air conduction shows 40 dB difference from bone conduction?
2. Is there a 10 dB or greater air bone gap?.