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20Q: Using the Aided Speech Intelligibility Index in Hearing Aid Fittings

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1.  The Speech Intelligibility Index (SII) is a measure of: the ratio of speech to background noise in a given signal the amount of speech that is available to a listener the lowest level that a listener can discriminate between two similar words hearing sensitivity

2.  In the SII calculation, which frequency range is given the most weight? low frequencies mid frequencies high frequencies ultra high frequencies

3.  Which of the following statements is true? The SII is incorporated into many hearing aid test systems The Count-the-Dots audiogram allows you to see the audibility of aided speech over different input levels The Articulation Index (AI) is a newer term for the SII that is used in hearing aid test systems With a good fitting to target, the SII should always be> 90

4.  To obtain an aided SII: Have the patient repeat 10 Spondees presented at average conversational level while wearing their hearing aids, and the percent correct score is the SII Measure aided thresholds in soundfield and plot them on a Count-the-Dots audiogram Use calibrated speech as a test signal with a probe-mic system to measure aided SII Using probe mic equipment, run a test of maximum output

5.  The ideal aided SII should be: 100% aligned with normative data as it will vary according to hearing level greater than 100 less than or equal to the unaided SII

6.  When fitting hearing aids to people with moderately-severe and severe-profound hearing losses: The aided SII should be about 90 If the SII is low, you should increase the gain and output to exceed targets to try and increase the SII The SII may be lower than expected as audibility is only one factor that goes into the calculation You should disregard the SII value as it has no relevance to power and superpower fittings

7.  When fitting a hearing aid to a child, one resource you can use to determine if your aided SII falls within the expected range of values is: Gus Mueller - send him a text message and ask him A free, downloadable score sheet that is part of the UWO PedAMP protocol, available at www. dslio.com AAA clinical guidelines for fitting amplification to children Submit a question to AudiologyOnline Ask the Expert

8.  One study found aided SIIs for adults DSL-5 fittings for with mild, moderate and moderately-severe hearing losses to range from: 79% to 63% to 47% 10% to 20% to 30% 90 - 100% for all hearing losses 0 - 10%

9.  The aided SII values with NAL and DSL: are exactly the same; SII does not vary by prescription are the same for severe and sloping losses, but vary with mild losses are similar for flat, mild losses and have more differences for severe and sloping losses should be close to 100 for most losses

10.  Lower than typical aided SII values for children: are a red flag that the fitting may be less than optimal are an indication of well-fitted amplification are fine as long as they are higher than unaided SII values is the primary goal when fitting amplification to children