Looking for help?

Visit the Support Center for additional downloads.
Download and run TeamViewer for technical live assistance.

Audiometry

Table of contents

  1. What is the QuickSIN test?
  2. Background
  3. Required equipment
  4. QuickSIN test procedure
  5. Aided QuickSIN
  6. QuickSIN results
 

What is the QuickSIN test?

The QuickSIN test provides an estimate of signal-to-noise (SNR) ratio loss in one minute. A list of six sentences with five key words per sentence is presented in four-talker babble noise. The sentences are presented at pre-recorded SNR ratios which decrease in 5-dB steps from 25 (very easy) to 0 (very difficult). These SNR ratios range from normal to severely impaired performance in noise.

 

Background

Difficulty with hearing in noise is a common complaint among hearing aid users.

Thus, the measurement of SNR loss is important, as you cannot determine a person’s ability to understand speech in noise based on the pure tone audiogram alone.

The QuickSIN test was developed to:

  1. Provide a one-minute estimate of SNR loss
  2. Provide a quick way for clinicians to quantify a patient’s ability to hear in noise
  3. Determine if extended high frequency emphasis improves or degrades understanding of speech in noise
  4. Assist professionals in choosing appropriate amplification and other assistive technologies
  5. Show that hearing aids with directional microphones improve speech intelligibility in noise
  6. Provide many similar test lists for use in clinical and research work
  7. Provide information useful in counseling patients and managing their expectations
 

Required equipment

  1. Headphones, insert phones, or a free field speaker
  2. Standalone AC40/AD629/AA222, or in hybrid mode using Diagnostic Suite
 

QuickSIN test procedure

QuickSIN test screen.

Figure 1: QuickSIN test screen.

The test is outlined below step-by-step, using the above-mentioned equipment, and with references to Figure 1 throughout.

 

1. Select QuickSIN

Press and hold the ‘Tests’ button and use the black scroll wheel to select QuickSIN.

 

2. Wave file

The audiometer will default to ‘Wave file’.

Press and hold ‘List’ to select the desired wave file.

You can use practice lists A, B, and C to familiarize with the test.

 

3. How to instruct your patient

You can use the script below for inspiration:

Imagine that you are at a party. There will be a woman talking and several other talkers in the background. The woman’s voice is easy to hear at first, because her voice is louder than the others. Repeat each sentence the woman says. The background talkers will become louder, making it difficult to understand the woman’s voice, but please guess and repeat as much of each sentence as possible.”

It may help to stress to the client to repeat anything they have heard, even if they have only heard one word from the sentence, as this may improve their score.

 

4. Presentation level

You may choose your own preferred test level.

We recommend 70 dB HL in clients with a pure-tone average (PTA) of 45 dB or below.

In clients with a PTA of 50 dB or above, you will need to exceed 70 dB HL without testing at an uncomfortable level for your client.

 

5. Begin the test

Press the play button to begin the test.

 

6. Scoring

In each list there are 6 sentences, each with 5 key words highlighted in bold.

You must score the client on how many of these key words the client correctly repeats back to you.

Thus, you can either score 0, 1, 2, 3, 4, or 5.

Once you have scored a sentence, the next sentence will be presented automatically.

 

7. Final score

Once you have scored all 6 sentences, you will get an SNR loss in dB.

You can use this to categorize the degree of SNR loss and for expected improvements with directional microphones.

More on this below.

 

8. Store the results

Save the QuickSIN test by clicking the ‘Save Session’ button.

 

9. Bonus step: Averaging

Averaging several QuickSIN lists (only lists 1-12 at the same intensity level) will improve the reliability of the results.

This will be particularly useful when comparing aided versus unaided or before versus after hearing aid adjustments.

 

Aided QuickSIN

It is possible to do an aided QuickSIN when using the audiometer via Diagnostic Suite, given the audiometer is free field calibrated.

Aided versus unaided is a useful tool to test the benefit of a hearing aid treatment in noisy environments.

To activate the aided function, select ‘Free Field’ as the transducer.

Click on the aided button (ear with hearing aid) to add an extra column to the scoring table.

You can see what this looks like in the next section.

 

QuickSIN results

The SNR loss is 25.5 minus the total score (Figure 2).

QuickSIN summary screen. Unaided total of 22, and aided total of 25. 3.5 dB SNR loss unaided, and 0.5 dB SNR loss aided.

Figure 2: QuickSIN results.

You can then categorize the SNR loss based on Table 1, which also shows the expected improvements with directional microphones.

SNR loss

Degree of SNR loss

Expected improvement with directional microphones

0-3 dB

Normal / near normal

May hear better than normal in noise

3-7 dB

Mild SNR loss

May hear almost as well as normal in noise

7-15 dB

Moderate SNR loss

Directional microphones help. Consider array mic

>15 dB

Severe SNR loss

Maximum SNR improvement is needed. Consider FM system

Table 1: SNR loss definitions.

 
June 2016

Table of contents

  1. What is speech audiometry?
  2. Background
  3. Speech detection threshold (SDT)
  4. Speech recognition threshold (SRT)
  5. Word recognition (WR)
  6. Required equipment
  7. Speech setup
  8. Test procedure
  9. Speech results
  10. Speech in noise
  11. Binaural speech
  12. References
 

What is speech audiometry?

Basic speech audiometry uses speech signals to assess a person’s ability to hear speech, discriminate between words, and recall words. Advanced speech audiometry dives into the comprehension of speech.

 

Background

Many hearing aid users report trouble hearing speech, especially in noisy situations.

In this light, speech testing is a good tool to assess why the patient is troubled in certain hearing environments.

Speech audiometry employs speech signals and can be used to examine the processing ability and if it is affected by disorders of the middle ear, cochlea, auditory nerve, brainstem pathway, and auditory centers of the cortex.

More advanced speech testing considers how speech is understood in the presence of noise, such as:

  • White noise
  • Speech noise
  • Babble noise

Using speech as the noise source can provide information on the signal-to-noise ratio (SNR) at which the patient can understand speech.

Other components such as the placement of the speech signal in relation to the noise source and the tonal differences between the speech signal and the masking signal are some of the things incorporated into advanced speech testing.

 

Speech detection threshold (SDT)

The speech detection threshold (SDT), also known as the speech reception threshold, is the level at which the patient can hear speech is present in 50% of the cases.

You can use the SDT as a cross-check of air conduction audiometry, which should closely agree with the pure‑tone average (PTA).

 

What is the pure-tone average (PTA)?

The PTA is the average of thresholds obtained at 500, 1000, and 2000 Hz.

For the PTA and SDT to ‘closely agree’, apply the following rules of thumb:

  • ±6 dB or less = good
  • ±7-12 dB = adequate
  • ±13 dB or more = poor
 

Speech recognition threshold (SRT)

The speech recognition threshold (SRT) examines at which level the patient can repeat 50% of the speech material (usually numbers or spondaic words) correctly.

Also, the SRT gives an index of hearing sensitivity and helps to determine the starting point for other supra-threshold measures such as word recognition (WR).

 

Word recognition (WR)

WR, also known as speech discrimination (SD), is a score of the number of words correctly repeated, expressed as a percentage of correct (discrimination score) or incorrect (discrimination loss).

You can also score this as a phoneme score to know which phonemes the patient has difficulty hearing at a particular intensity level.

This is helpful for counseling and rehabilitation purposes.

 

Discrimination score / discrimination loss

You can either record this score in the Diagnostic Suite or with the audiometer keyboard on our standalone devices.

 

In the suite

Press the checkmark or the left arrow key to store a word as correctly repeated. Press the ‘X’ or the right arrow key to store a word as incorrectly repeated. Press the circle or ‘S’ on your keyboard to store the speech threshold in the speech graph (Figure 1).

Three buttons: checkmark, X, and circle.

Figure 1: Speech discrimination in the Diagnostic Suite.

 

On standalone devices

Press ‘Incorrect’ to store the word as incorrect or press ‘Correct’ to store the word as correct (Figure 2).

Two buttons: incorrect and correct.

Figure 2: Speech discrimination with audiometer keyboard.

 

Phoneme score

When the speech material is indexed according to the number of phonemes in each word, the according soft key numbers will activate.

So, for a word with two phonemes, the soft keys ‘0’, ‘1’, and ‘2’ will be available to score.

When you score the word with the use of phonemes, the number of correct phonemes will appear below the word (Figure 3).

Three words with three phonemes each: fish, duck, and gap.

Figure 3: Words and their number of phonemes.

The phoneme score is calculated as a percentage: correct phonemes relative to total number of phonemes.

 

Required equipment

(1) Headphones, insert phones, or free field speakers

(2) A microphone, external sound player, or built-in wave files

(3) Talk back microphone and talk forward microphone

 

Speech setup

When running the speech test using wave files, you can present words in manual, continuous, or time out mode.

 

1. Manual mode

This allows you to manually press the tone switch/enter button to present the word and then score it as incorrect or correct before moving on to the next word.

 

2. Continuous mode

In this mode, the next word will automatically be presented after scoring incorrect or correct.

 

3. Time out mode

In this mode, the word played will be scored as either correct or incorrect if you do not enter the score within 1 to 5 seconds.

 

Test procedure

The procedure is outlined below step-by-step and is specific to our equipment.

 

Step 1

Before performing speech audiometry, you may wish to do the tone audiogram.

This provides valuable predictive information for speech testing, including information about when you need to apply masking.

 

Step 2

Press the ‘Tests’ button and select the ‘Speech’ test.

If needed, select the ‘Measurement type’ (WR1, WR2, WR3, SRT), ‘Type’ of measure (word, numbers, multi‑syllabic numbers, multi‑syllabic words), and ‘List’ of words using the soft buttons.

Select the intensity levels for channel 1. If you need to apply masking, configure channel 2 also.

 

Step 3

Explain to your patient that he/she will now hear some words/numbers/sentences though the earphones/free field speakers.

Instruct your patient to repeat what is said even though it may be very soft.

Encourage your patient to guess even if they are unsure about the word/number/sentence.

When performing the speech test in noise, instruct your patient to focus on the speech, not the noise.

 

Step 4

Press ‘Start’ to start presenting the words, numbers, or sentences.

Based on the settings for speech, you can score the response as ‘Correct’, ‘Incorrect’, or as the number of correct phonemes.

 

Step 5

Click on ‘Store’ to store the results.

 

Speech results

You can display the results in table mode or graph mode.

 

1. Table mode

Table mode allows for several SRTs using different test parameters, such as transducer type, test type, intensity, masking, and so forth (Figure 4).

Table with the following columns: transducer, type, dB, Mask, Score, and Aided.

Figure 4: Table mode.

 

2. Graph mode

When showing the SRT in graph mode, the speech audiogram calculates the SRT value, which is the distance in dB from the point where the normative curve crosses 50% to the point where the speech curve crosses 50% (Figure 5).

Speech audiogram. Graph is dB HL as a function of speech recognition.

Figure 5: Graph mode.

The SRT value is how much you need to turn up the level compared to normal for the patient to be able to repeat 50%.

Use the m-curve for multi-syllabic words and the s-curve for single-syllabic words.

You can edit the curves according to the normative data you wish to use in the speech settings.

Note that the normative curves change based on the speech material.

Thus, you must ensure that WR1, WR2, or WR3 are linked to single- or multi-syllabic words to show the SRT.

Calculating the WR SRT is only available when using the suite.

 

Speech in noise

Problems understanding speech in noise is a common complaint from people with hearing loss.

Speech in noise testing provides useful information about the impact of the hearing loss on the patient’s ability to communicate.

It also provides information about whether the patient is getting the expected benefit from the hearing aids when communicating in noisy environments.

You can test the patient in a speech in noise environment using a free field setup to present the speech signal and noise signal from the same speaker or separate speakers.

Either present the signal and noise to the same ear with AC40 or select the speech in noise test with AD629.

 

Binaural speech

If you want to present the speech signal to both ears at the same time, select the same output for both channels with AC40.

With the AD629e, perform binaural speech by choosing the test ‘Speech-Ch2On’.

 

References

Stach, B.A (1998) Clinical Audiology: An Introduction, Cengage Learning.

November 2016

What is the Stenger test?

The Stenger test uses the auditory phenomenon ‘The Stenger Principle’, which states that a person will only hear the louder of two identical tones presented to both ears at the same time. The test is useful in patients with a suspected unilateral non-organic hearing loss, also known as malingering.

You can perform the test with two tuning forks, but we recommend using a two-channel audiometer for better accuracy.

 

What is malingering?

Malingering a hearing loss is when a patient does not respond to the stimuli on purpose. This causes an audiogram that shows a hearing loss without this being the case.

 

Why would a patient fake a hearing loss?

It is hard to say why a person may choose to fake a hearing loss. The cause can be psychological, such as the need for attention. It can also be driven by motive, such as hearing loss compensation.

Whatever the cause or motive, the Stenger test is a good test to identify malingering.

 

Signs of malingering

[1] The audiogram is completely flat.

[2] The thresholds keep moving up and down.

[3] The audiogram shows a large hearing loss, but the patient does not have any problems hearing you when you speak.

 

How to perform a Stenger test

Given ‘The Stenger Principle’, you perform the test by presenting tones to both ears at the same time. Set the intensity level to 10 or 20 dB above the threshold in the good ear and 10 or 20 dB below the threshold in the poor ear. Keep the intensity level in the good ear fixed while increasing the intensity in the poor ear in 5-dB steps. The point at which the patient responds in the poor ear will allow you to plot the extent of the non-organic component.

20 dB above/below threshold is used in Figure 1.

20 dB intensity level from channel 2, which is 20 dB above 0 dB threshold in the right (good) ear. 40 dB intensity level from channel 1, which is 20 dB below 60 dB threshold in the left (poor) ear.

Figure 1: Stenger test example with a two-channel audiometer.

The speech Stenger test is identical, but with the use of speech material instead.

 

Caveat

Instruct your patient the same way as you would do with standard pure tone audiometry.

Do not tell your patient that the stimulus is presented to both ears at the same time.

 

What is a negative Stenger test result?

If the hearing loss in the poor ear is genuine, the patient will keep responding to the signal presented to the good ear (negative Stenger).

 

What is a positive Stenger test result?

If the patient is simulating the hearing impairment, he/she will not respond to the stimuli. This shows that the tone presented to the poor ear is louder than the patient’s actual threshold (positive Stenger).

 

Conclusion

The Stenger test is a useful test for quick identification of a unilateral non-organic hearing loss.

It also avoids challenging the patient, as you can move seamlessly from standard pure tone audiometry into the Stenger test without the patient knowing.

July 2017

Table of contents

  1. What is masking?
  2. Interaural attenuation
  3. Masking example
  4. Required equipment
  5. Test procedure
  6. Auto masking
  7. Masking help
  8. References
 

What is masking?

In cases where you detect a symmetrical hearing loss, traditional audiometry without masking is usually enough.

In cases of asymmetrical hearing loss, one cannot be certain that the intended ear is the one detecting the sound.

To prevent this phenomenon causing an erroneous measurement, you can use masking noise to occupy the good ear (non-test ear) while testing the other ear [1-3].

Masking can be applied to air conduction, bone conduction, and speech audiometry.

 

Interaural attenuation

The need to mask the better hearing ear is linked to the interaural attenuation, which equals the amount of attenuation the sound is exposed to on its way through the skull.

Even though the interaural attenuation is very individual and varies with frequency, it can on average be estimated to be a minimum of 40 dB for supra-aural headphones and 50 dB for inserts.

In bone conduction, the interaural attenuation is a minimum of 0 dB, which means that the stimulus may cross over, and this is what one should assume.

 

Masking example

In patients with normal hearing on one ear, but a moderate to severe hearing loss on the other, there is a potential risk of the good ear hearing the tone when trying to test the damaged ear.

That is, the sound vibration may travel through the head and be heard by the opposite good ear when the vibrations of the signal are large enough.

Thus, you would be measuring the thresholds from the wrong ear.

This could be the case in Figure 1, where the right ear (better ear) should be masked while reassessing the left ear (poorer ear).

Audiogram showing a 50 dB HL asymmetry between right and left at the higher frequencies.

Figure 1: Asymmetrical hearing loss; right ear is better than left ear.

Masking is also needed to differentiate between sensorineural, conductive, and mixed hearing losses.

In Figure 1, it is unknown if the loss in the left ear is sensorineural, conductive, or mixed.

The origin will be revealed by obtaining the bone conduction threshold for the left ear while occupying the right ear with masking.

 

Required equipment

(1) Headphones or insert phones

(2) Bone oscillator

 

Test procedure

The procedure is outline below in several steps, some of which are specific to Interacoustics equipment.

 

Step 1

Perform air conduction audiometry unmasked for both ears.

 

Step 2

Perform bone conduction audiometry unmasked for both ears.

 

Step 3

Apply masking if needed:

(1) In case of an air-bone gap of 15 dB or more, you must reassess the bone conduction threshold while applying masking to the non-test ear.

(2) If the difference between the air conduction threshold in the poor ear and the bone conduction threshold in the good ear exceeds an interaural attenuation of 40 dB (50 dB if using insert phones), you will need masking for air conduction audiometry in the poor ear.

 

Step 4

Select NB in channel 2.

 

Step 5

Select which ear to mask and choose the appropriate masking transducer (headphones or insert phones).

This will activate the masking noise.

 

Step 6

Proceed to do a masked threshold search and press ‘Store’ once you have obtained a correct threshold.

The symbol will appear in the audiogram as masked.

There are many ways of applying clinical masking.

Which one to use is your decision.

Regardless of the masking method, use channel 2 to occupy the better ear.

 

Step 7

To display the masking level information on screen, select ‘Mask info’.

 

Example

If we refer to Figure 1, channel 2 should be set to the right ear (non-test ear) using the preferred masking stimulus (usually NB).

Ensure that ‘Rev’ is active to ensure that the masking noise is continuous.

Channel 1 should be set to the left ear (test ear) using the preferred stimulus (usually tone).

The masking frequency will automatically change along with the tone frequency when masking is turned on.

You can set the masking and tone frequencies by using the frequency up/down buttons.

While trying to establish the true threshold of the left ear, the right ear is now distracted with noise.

When storing a threshold while masking, the final masking level is stored in the masking table under the ear that is being tested.

The term ‘effective masking’ in this situation refers to the fact that the narrow band noise level was loud enough to effectively mask a pure tone of the indicated level heard by the masked ear.

 

Auto masking

Interacoustics auto masking is a tool in the Diagnostic Suite to mask with correct masking levels.

When you have enabled auto masking, the system controls channel 2 and sets it to the appropriate intensity level.

Activate auto masking by selecting the icon that shows a mask with the letter A (Figure 2).

Auto masking icon.

Figure 2: Auto masking icon.

Green indicates that masking is correctly applied (Figure 3).

Correct masking, indicated by a green circle.

Figure 3: Correct masking.

Amber indicates that the masking intensity should be louder and that you need to activate the extended frequency range (Figure 4).

Masking noise should be louder, indicated by an amber circle.

Figure 4: Masking noise should be louder.

Purple indicates that masking is needed but non-feasible (Figure 5).

Masking is non-feasible, indicated by a purple circle.

Figure 5: Masking non-feasible.

 

Caveats

(1) Be aware that patients need proper instructions before audiometry with masking is undertaken.

(2) The switching-on-and-off of the masking noise may be uncomfortable to some patients and cause fatigue.

(3) Masking is not recommended in young children, elderly patients, or difficult-to-test patients, because confusion about the application of masking noise may lead to false responses.

(4) You can avoid most errors by measuring the best ear first and completing air conduction on both ears before measuring bone conduction.

(5) Be careful when storing thresholds where masking was non-feasible, where the risk for crossover hearing is high. In these cases, you should store a no-response at the loudest intensity where masking was still possible (by pressing the N key).

 

Terminology

AC

Air conduction test ear

ACc

Air conduction non-test ear

BC

Bone conduction test ear

BCc

Bone conduction non-test ear

IaA

Minimum interaural attenuation

IaAc

Minimum interaural attenuation contra transducer

Dial

Dial setting test ear

Dialc

Dial setting non-test ear (masking level)

Table 1: Masking terminology.

 

Is masking required?

Masking is recommended when the presentation at the test ear can be heard by the non-test ear, or in a formula:

Dial – IaA ≥ lowest of the two ACc/BCc values

 

Is the masking level too low?

The applied masking level is too low when it does not match the intensity at which the test signal is heard in the non-test ear, or in a formula:

Dialc – (ACc – BCc) < Dial – IaA

 

Is the masking level too high?

The applied masking level is too high when it is so loud that it potentially is heard by the test ear, or in a formula:

Air conduction

Dialc – IaAc ≥ Dial – (AC – BC)

Bone conduction

Dialc – IaAc ≥ Dial

 

Is masking impossible?

Masking is not possible when the needed masking level results in ‘over masking’ at the same time:

Air conduction

Dial + (ACc – BCc) – IaA ≥ Dial – (AC – BC) + IaAc

Bone conduction

Dial + (ACc – BCc) – IaA ≥ Dial + IaAc

Nor is masking possible when the needed masking level is higher than the maximum level of the masking transducer:

Dial + (ACc – BCc) – IaA > maximum available Dialc

 

Recommended masking intensity

If masking is required and possible, the recommended masking intensity is the minimum required masking level plus a fixed preferred amount:

Recommended Dialc = Dial – IaA + (ACc – BCc) + preferred extra amount

The recommended masking level is adjusted for values that cannot be reached by the masking transducer due to maximum values.

When you use the auto masking feature, masking intensities are set to the recommended intensity.

 

Masking help

Interacoustics masking help is a tool in the Diagnostic Suite to make it easier to decide on a safe and correct masking intensity.

When masking help is activated, a status light on channel 2 indicates if masking is applied correctly.

Activate masking help by selecting the icon with the mask (Figure 6).

Masking help icon.

Figure 6: Masking help icon.

Grey indicates that the masking help is not active (Figure 7). Green indicates that masking is correctly applied.

Masking help not active, indicated by a grey circle.

Figure 7: Masking help not active.

Optionally, masking help can give a suggested masking level.

The example here suggests 85 dB, but 75 dB is also within the safe masking range (Figure 8).

75 dB masking level is adequate, indicated by a green circle, but the software suggests 85 dB.

Figure 8: 75 dB masking level is adequate, but 85 dB is suggested by the software.

Amber indicates too much or too little masking, easier clarified by the suggested masking level (Figure 9).

75 dB masking level is incorrect, indicated by an amber circle, and the software suggests 85 dB.

Figure 9: Too much or too little masking. Too little in this case, with 85 dB suggested by the software.

Purple indicates that masking is needed but non-feasible (Figure 5).

 

Frequency-specific interaural attenuation

The interaural attenuation values used by the masking help feature are frequency-specific and you can customize them in the setup.

Table 2 shows the default interaural attenuation values (IaA).

Frequency (Hz)

125

250

500

750

1000

1500

2000

3000

4000

6000

8000

IaA headphones (dB)

35

40

40

40

40

40

40

45

50

50

50

IaA inserts (dB)

50

50

50

50

50

50

50

50

50

50

50

IaA bone (dB)

0

0

0

0

0

0

0

0

0

0

0

Table 2: Default interaural attenuation values.

 

Caveats

(1) Experienced audiologists should not use the option of viewing a suggested masking level.

(2) The masking help indicates if masking is performed correctly with the information given at the time of the measurement. You can avoid most errors by measuring the best ear first and completing air conduction on both ears before measuring bone conduction.

(3) Although clinicians tend not to apply masking for bone conduction in instances where the air-bone gap is less than 15 dB in the better ear, the masking help feature may recommend masking (Figure 10).

Air-bone gap is only 10 dB, but the software suggests a masking level of 45 dB.

Figure 10: Air-bone gap is less than 15 dB in the test ear, but the masking help feature suggests a masking level of 45 dB.

 

References

[1] Stach, B.A (1998). Clinical Audiology: An Introduction. Cengage Learning.

[2] J. Katz (2002). Handbook of Clinical Audiology (5th ed.). Lippincott Williams & Wilkins.

[3] British Society of Audiology (2018) Pure tone air and bone conduction threshold audiometry with and without masking. Retrieved March 31, 2021, from https://www.thebsa.org.uk/resources/pure-tone-air-bone-conduction-threshold-audiometry-without-masking/.

June 2016

What is the SISI test?

SISI is a test of a person’s ability to recognize 1 dB increases in intensity during a series of bursts of pure tones presented 20 dB above the pure tone threshold for the test frequency. You can use the SISI test to differentiate between cochlear and retrocochlear disorders, as a patient with a cochlear disorder will be able to perceive the increments of 1 dB, whereas a patient with a retrocochlear disorder will not.

 

How to do the SISI test

The following steps will outline how to do the test using a two-channel audiometer.

You will also need headphones or insert phones and a response button.

Figure 1 shows what the test screen looks like in our software.

SISI test screen. Patient has scored 85% and 80% on the right ear for the 1 kHz and 1.5 kHz frequencies, respectively.

Figure 1: SISI test screen.

 

Step 1

Select a tone or warble stimulus in channel 1.

If you suspect cross hearing, then you should present masking in channel 2.

 

Step 2

Select the desired test frequency and set the input level 20 dB above threshold.

 

Step 3

In the most common type of SISI test, the incremental steps are 1 dB.

You can change these to 0, 2, or 5 dB.

0 dB is for when you are uncertain about your patient’s responses, while 2 or 5 dB are good for trialing that your patient understands the test procedure.

 

Step 4

Before testing, explain to your patient that he/she will now hear a series of tones.

Instruct your patient to push the response button if they think the loudness of the tone changes.

 

Step 5

The system will automatically count the number of reactions from the patient.

Note that the system needs 20 presentations to calculate a SISI score.

Repeat the test for all desired test frequencies.

 

How to interpret SISI results

Expanding upon the previous definition, SISI is a measure of one’s ability to tell the difference between the loudness of sound.

The test takes advantage of the increased sensitivity to loudness changes in patients with cochlear losses, which is due to cochlear recruitment.

In someone with a retrocochlear loss, we do not expect the same degree cochlear recruitment, meaning they would be less sensitive to changes in the loudness of sound.

The score is a percentage, which expresses the number of 1 dB increments the patient detected out of the twenty in total, multiplied by five:

  • 70-100% correct = high (cochlear loss)
  • 20-70% correct = inconclusive
  • <20% = low (retrocochlear loss)
June 2016

What is the ABLB test?

ABLB is a test to detect perceived loudness differences between the ears and is useful in patients with unilateral hearing loss. The ABLB test can identify cochlear recruitment and decruitment. Recruitment will appear as a compressed dynamic range compared to the reference ear, while decruitment will appear as an expanded dynamic range compared to the reference ear.

 

How to do the ABLB test

You perform the test by alternating a fixed frequency between the two ears, keeping the intensity in the good ear constant while varying the intensity in the impaired ear.

The patient’s task is to state whether the signal is ‘softer than’, ‘louder than’, or ‘equal’ in loudness to the good ear.

The test begins at 20 dB HL in the good ear.

Then alternate the side and play the same sound to the poorer ear. With a two-channel audiometer from Interacoustics, set the ‘Man Rev’ button to ‘Rev’. This will ensure continuous presentation of the tones, without having to stimulate manually.

Modulate the sound in the poorer ear until your patient describes the loudness as the same as that in the good ear.

Once you achieve equal loudness, increase the intensity in 20 dB steps until you reach either the patient’s tolerance level or the maximum output of the audiometer.

 

How to interpret ABLB test results

The results are expressed on a ladder chart as in Figure 1.