Trouble Identifying Tinnitus Frequency (Hz)

So I'm trying to figure out just just at what frequency my T is in and I'm having a lot of issues with it.

Problem is- I have a hearing loss, I have since birth, and I am deaf in the tone that my T is in. My audiogram looks like a sick slide that just starts the moment you hit the high tones and it just keeps going down from there. This is a sound that my brain has a lot of difficulty recognizing much less pinpointing the Hz for it and I was wondering if anyone had any tips from experience.

I work at an audiology office (front desk) and literally I had the poor intern work with me in the booth for like a good half hour trying to figure out what noise my brain was making up for me to hear and we couldn't do it- it was super frustrating.