For people looking for treatment for long-term tinnitus, notched sound therapy has been statistically shown to help by reducing brain activity in relation to the perceived tinnitus frequencies (https://pmc.ncbi.nlm.nih.gov/articles/PMC8832119/). In other words, it doesn't go away, but it becomes less "important" to the auditory centers.

There are various professionally provided therapies of this style, but there are also simple self-therapy apps that find the perceived frequencies and then play white noise or a music library with the sound adjusted to produce the notched effect in that small frequency window. For example: https://audionotch.com/ https://www.tinnitusnotch.com/ https://www.tinnaway.com/