Yeah the TFI doesn't measure the characteristics of tinnitus at all. TFI is very much a quality-of-life questionnaire more than an actual perception measurement. It is a 25-item questionnaire totaling 100 points, and broken into sections to measure how a patient's tinnitus affects their ability to cope, concentrate, sleep, communicate, socialize, etc. It has been validated by research as a consistent tool for monitoring how a patient is living with tinnitus.
I suspect you will be correct that high-frequency tinnitus (8 kHz and above) may see a higher rate of improvement than mid-low frequency tinnitus.
From a statistical significance standpoint, it might be that high-frequency tinnitus, which seems pretty common and most bothersome from anecdotes on this forum, may result in a dramatic drop in TFI from a baseline score. I also have theorized that simply increasing the signal from damaged hair cells anywhere in the cochlea may help to reduce the perception of tinnitus if it is lower in the frequency range. So, that may also help reduce the TFI score moderately.
I definitely do not expect to see some ground-breaking p-value even when the final data is released. But I would expect them to highlight patients that saw dramatic drops in their TFI, indicating that it helped people the most where the tinnitus and repaired damage had a high correlation.
Of note, Clinical Significant TFI score drop is 14 points with bi-lateral tinnitus. For one treated ear, they may assume a 7 point drop is considered significant.
Also, this is how a clinician is normally trained to translate the TFI score into understanding the severity of a patient's tinnitus:
- Mean score of 14 (range 0-17) not a problem.
- Mean score of 21 (range 18-31) small problem.
- Mean score of42 (range 32-53) moderate problem.
- Mean score of 65 (range 54-72) big problem.
- Mean score of 78 (range 73-100) very big problem.