Indications of non-organic hearing lossIndications of non-organic hearing loss

Inconsistent behavior and performance on Inconsistent behavior and performance on tests.tests.

Poor test-retest reliabilityPoor test-retest reliability

Incompatibility between PTA and SRTIncompatibility between PTA and SRT

Acoustic reflexes found at very loss Acoustic reflexes found at very loss sensation levelssensation levels

Tests for non-organic hearing lossTests for non-organic hearing loss

Objective tests:Objective tests:Acoustic reflexAcoustic reflexAuditory evoked potentialsAuditory evoked potentialsOAEOAE

Behavioral tests:Behavioral tests:Stenger (Most popular)Stenger (Most popular)LombardLombard

Stenger testStenger test

Theory: If two sounds of the same frequency are Theory: If two sounds of the same frequency are presented simultaneously to both ears, only the presented simultaneously to both ears, only the louder tone will be perceived.louder tone will be perceived.

Used in case of assymetrical hearing loss with at Used in case of assymetrical hearing loss with at least 25 dB difference between ears.least 25 dB difference between ears.

StepsSteps

Measure unmasked threshold for both ears separately.Measure unmasked threshold for both ears separately.

Present a 10 dB SL tone in better ear: Response Present a 10 dB SL tone in better ear: Response

Present a 10 dB below threshold in poorer ear: No Present a 10 dB below threshold in poorer ear: No responseresponse

Now, both tones presented simultaneously Now, both tones presented simultaneously

Results of Stenger testResults of Stenger test

Negative Stenger: If response, then, no non-organic Negative Stenger: If response, then, no non-organic hearing loss hearing loss

Positive StengerPositive Stenger: If no response, implies that the : If no response, implies that the tone was heard in poorer ear but patient unwilling tone was heard in poorer ear but patient unwilling to respond. Unaware of tone in better ear because to respond. Unaware of tone in better ear because of Stenger effect. of Stenger effect.

Can be done with pure tones and speech.Can be done with pure tones and speech.

Can also be used to Can also be used to approximateapproximate real thresholds by real thresholds by finding the minimum level at which a positive finding the minimum level at which a positive Stenger is obtained.Stenger is obtained.

Lombard testLombard test

Theory: In the presence of background noise, Theory: In the presence of background noise, individuals speak louder.individuals speak louder.

Ask patient to read or speak aloud.Ask patient to read or speak aloud.

Masking noise is added and gradually increased Masking noise is added and gradually increased in level.in level.

If patient increases speech level, then masking If patient increases speech level, then masking noise heard. noise heard.

Diagnosis of non-organic hearing loss made Diagnosis of non-organic hearing loss made based on level of noise and measured thresholds.based on level of noise and measured thresholds.

Other testsOther tests

Varying intensity story test: Present parts Varying intensity story test: Present parts of story above threshold and parts below of story above threshold and parts below threshold, ask questions based on story.threshold, ask questions based on story.

Count the number of tones heardCount the number of tones heard

Yes/No method (for children)Yes/No method (for children)