Stenger test: Assessing non-organic hearing loss

Table of contents

• What is the Stenger test?
• When to perform the Stenger test
• How to perform the Stenger test
• Interpreting Stenger test results
• Managing a non-organic hearing loss
• Frequently asked questions

What is the Stenger test?

The Stenger test is a behavioral assessment designed to identify a non-organic component in unilateral or markedly asymmetric hearing loss [1, 3]. The Stenger test is performed using a two-channel audiometer such as the Equinox Evo to present two simultaneous stimuli to the patient – one in each ear – to assess whether true thresholds have been established with other audiometric measurements [3].

What is non-organic hearing loss?

Non-organic hearing loss, also known as functional hearing loss, is commonly thought of as a form of ‘malingering’ or ‘faking’, and is rapidly becoming less commonly used due to its often-unhelpful connotations. In reality, non-organic hearing loss can originate from very real experiences or can be a sign of possible psychiatric or social factors which may need further attention [1].

Stenger phenomenon

The Stenger test exploits the ‘Stenger phenomenon’: When identical tones are delivered at the same time to both ears but at different intensities, the listener should only perceive the louder tone. In a suspected functional hearing loss, a patient may fail to respond when the louder stimulus is delivered to the ‘poorer’ ear. This result is recorded as a positive Stenger test [2, 3].

When to perform the Stenger test

The Stenger test is recommended to perform in the following scenarios:

• High levels of interaural threshold difference.
• Unreliable or inconsistent pure tone audiometry responses.
• Medico-legal situations which may present motive to alter responses.

Please be aware of the following limitations:

• Use with caution in children, in which Stenger results can be less reliable [2].
• You cannot complete the Stenger test in those with bilaterally elevated symmetrical hearing thresholds (even if you suspect non-organic origin).

How to perform the Stenger test

In the following, we will discuss these components of performing the Stenger test:

• Equipment requirements
• Preparation steps
• Test procedure

Equipment requirements

To perform the Stenger test, you need a two-channel audiometer such as the Equinox Evo with the ability to present two sounds of different levels simultaneously via the left and right channels. It is vital that your audiometer is properly calibrated and has had Stage A checks performed to ensure reliability and validity of the test [4, 5].

You can use supra-aural or insert earphones for the Stenger test but not bone conduction. A patient response button is recommended, but you can perform the test with an alternative response method (such as verbal response) if required [3].

Finally, two-way communication can be helpful if your patient is in a separate sound booth to make re-instruction or gentle encouragement easier. Many audiometers feature ‘talk-forward’ and ‘talk-back’ capabilities which can be helpful with this test.

Preparation steps

First, measure a conventional pure tone audiogram and note any irregularities in the patient responses leading you to suspect a functional hearing loss (inconsistent responses, unexpected asymmetry etc.).

Second, select your starting frequency for the Stenger test by reviewing the levels of asymmetry present at each frequency. You should select a frequency with a larger apparent asymmetry. If the degree of asymmetry is similar across the audiogram, the starting frequency should not have a significant effect on the test [11].

Third, instruct your patient. Keep the instructions very simple to avoid priming erroneous responses. Example instructions could be: “I will now play you some more sounds, press the button whenever you hear a tone.”

Test procedure

Below, we will cover the step-by-step procedure for the Stenger test (eight steps in total).

Step 1

Select your starting frequency.

Step 2

Reconfirm your baselines in both ears, starting with the apparent better ear.

Step 3

Calculate your starting intensity for the Stenger test in both ears:

• For the poorer ear, use channel 1 and select a level 10-20 dB HL below the recorded threshold.
• For the better ear, use channel 2 and select a level 10-20 dB HL above the threshold.

Step 4

Present the stimuli simultaneously. If you are using the Affinity/Equinox Suite, select ‘Sim’ to enable simultaneous presentation.

Step 5

Record the response:

• Negative Stenger if the patient pressed the button in response to simultaneous presentation.
• Positive Stenger if the patient did not press the button in response to simultaneous presentation.

Step 6

Repeat to check for consistency.

Step 7

Repeating steps 4 to 6, keep the intensity level of the better ear fixed and increase the intensity for the worse ear in 5-dB steps.

Step 8

Repeating steps 2 to 7, test other frequencies if clinically relevant.

Interpreting Stenger test results

In cases of a positive Stenger test, objective hearing assessments can be valuable to identify whether inconsistencies are due to testing irregularities or a behavioral non-organic hearing loss. Electrophysiological tests such as ASSR or ABR are robust objective methods for threshold estimation [1, 7].

Ipsilateral acoustic reflexes, whilst not a threshold assessment tool, could be useful if you suspect that hearing may be within or close to normal limits in the poorer ear. However, it is important to interpret these results with caution, as you will still get a positive Stenger test if – for example – a mild or moderate hearing loss is being exaggerated.

Otoacoustic emissions similarly are not a thresholding tool but can also help in cases where you suspect normal hearing.

Table 1 summarizes how to interpret and act on Stenger test results.

Table 1: Interpreting Stenger test results.

Managing a non-organic hearing loss

Given that the Stenger test is primarily an assessment for the presence or absence of a non-organic hearing loss, it is worthwhile taking some time to consider the further management of such patients.

Empathize with your patient

It is important to recognize that non-organic hearing loss can be a very real and concerning experience for the person experiencing it. You should therefore not undermine their experience by dismissing their reports of hearing loss, even when there does not appear to be a physiological basis for this experience.

Keep calm and non-confrontational

You should explain the results and the apparent inconsistencies to your patient in a calm and non-confrontational manner. Some sources suggest acknowledging the apparent hearing loss as real, but you can give reassurance at a high likelihood of recovery [1]. However, the patient’s presentation and your own professional judgement should always inform your approach to the debrief.

Remain factual

When reporting results of a Stenger test, ensure that you remain factual and avoid casting judgement or speculation. Record the intensity, frequency, and number of positive Stenger tests performed and confirm your conclusions with objective cross-checking measures if possible [5-7, 10].

Assess the patient’s broader clinical picture

Non-organic hearing loss can also be a sign of underlying psychiatric issues. It is therefore appropriate to assess the patient’s broader clinical picture to identify potential need for onward referral to appropriate mental health services. In most cases, however, simple monitoring and reassurance is sufficient to lead to a positive outcome.

Frequently asked questions

Below, we will cover a few frequently asked questions on the Stenger test.

Is a positive Stenger proof of ‘malingering’?

Not necessarily. The Stenger test indicates a functional (non-organic) component to a behavioral hearing loss.

Intent behind this can vary from conscious exaggeration (a decision to make hearing appear worse than it is) to an unconscious conversion (a genuine belief that their hearing is worse than it is, leading to changes in behavior).

It is therefore important to manage the patient appropriately with calm and constructive debriefing and facilitate appropriate further management.

Does a negative Stenger rule out non-organic hearing loss?

Not entirely. The sensitivity of the Stenger test is not perfect and false negatives can occur. Ensure you consider the whole clinical picture and if in doubt, proceed with caution and consider objective measures [8, 9].

What interaural difference is recommended to perform a Stenger test?

Guidance on levels of difference varies. Generally, the larger the apparent interaural difference, the more consistent the results will be. A minimum difference is typically considered to be 20 dB HL at the frequency being detected if testing with pure tones.

Is there a maximum interaural stimulus level difference at which the Stenger test is still informative?

When presenting different intensity sounds between the ears, the question of masking can often arise. You should not perform masking with a Stenger test. Considering again the purpose of the test, a positive result is when a person does not respond when they should be hearing a sound.

In a case of genuine asymmetrical hearing loss leading to cross-hearing, this individual will cross-hear into the better ear and therefore should press – meaning that cross-hearing should not present significant impact upon the outcome of the Stenger test.

Can I perform a Stenger test with a single-channel audiometer?

Generally, no. To perform the test, you need to be able to present two independent stimuli simultaneously. Single channel audiometers generally do not have the ability to present stimuli at different levels in each ear at the same time.

References

[1] Hussain, S. A. S., & Hohman, M. H. (2023–2024). Nonorganic (functional) hearing loss. StatPearls Publishing.

[2] Norrix, L. W., Rubiano, V., & Muller, T. (2017). Estimating nonorganic hearing thresholds using binaural auditory stimuli. American Journal of Audiology, 26(4), 486–495.

[3] Gelfand, S. A., & Calandruccio, L. (Eds.). (2023). Essentials of audiology (5th ed.). Thieme.

[4] British Society of Audiology. (2022). Minimum training guidelines – Basic audiometry and tympanometry.

[5] British Society of Audiology. (2018, August). Recommended procedure: Pure-tone air- and bone-conduction threshold audiometry with and without masking.

[6] British Society of Audiology. (2025, February). Recommended procedure: Tympanometry and acoustic reflex thresholds (Minor revision).

[7] British Society of Audiology. (2023, August). Practice guidance: Auditory steady-state response (ASSR) testing.

[8] Durmaz, A., Karahatay, S., Satar, B., Birkent, H., & Hidir, Y. (2009). Efficiency of Stenger test in confirming profound, unilateral pseudohypacusis. Journal of Laryngology & Otology, 123(8), 840–844.

[9] Arslan, H. H., Edizer, D. T., Cebeci, S., & Erdal, M. (2014). Diagnostic utility of Stenger test: Reappraisal of its value. International Tinnitus Journal, 19(1), 57–62.

[10] British Society of Audiology. (2023, August 31). Recommended procedure: Clinical application of otoacoustic emissions (OAEs).

[11] Boyd, P. J., Rowson, V. J., & Reeves, D. (1991). Application of phase-induced lateralization to the Stenger test.