The SII is a quantification of the proportion of speech information that is both audible and usable for a listener. It is a percentage (between 0% to 100%), and is correlated to the intelligibility of speech. For instance, for understanding words in sentences, an SII score of 25% would predict that about half of the speech for that level will be intelligible for the patient. For an SII score of 80%, we would predict that most of the speech will be intelligible. The prediction will vary depending on the speech signal of interest.
Speech Intelligibility Index (SII) and Percentile Analysis: Must-Have Tools in Your Fitting Software.
The SII values on your audiogram are 14% and 23%.
There are also four word list values provided (two per ear) with 100% scores.
For myself, I’d consider that 100%. But this is also a mystery to me.