You're exactly right. Although the model shown simplifies the concept a fair bit [ The Auditory Cortex also has a feedback loop to the MGN, otherwise asynchronous neurons firing in the auditory cortex area and creating the phantom T sound, would never reach the amygdala] it posits the conjecture that the brain will filter out repetitive
non harmful stimuli after a while.
Think of it like auditory signals being like marbles rolling down a channel. Normally the cochlea creates the marble and it rolls into MGN. [ In the case of a T the signal marbles are being fed back to the MGN]
The MGN copies the marble and sends one to the auditory cortex and one through the amygdala. As it passes through the amygdala it's evaluated for emotional content and if it's deemed to have some, it has a little "attachment" added which says : fast track to PFC for heuristic processing! [basically being made to use an evolutionary hardwired fast response track operating on autopilot] it hit's the PFC 300ms seconds before the other marble arrives and shout's "incoming, watch out!" and the first marble when it arrives receives full awareness (you're aware of the sound of the T)
The reason for this is that your ancestors emotional programmings were a quick and easy way to protect your genes from harm or promote your survival.
Unfortunately when an "emotional attachment" is fixed onto your little marble as it passes through the amygdala its "too big" to fit through the little hole letting it back in your MGN for signal cancellation.
Habituation is the removal of the attachment over time. If the stimulus is harmless and nothing of any note happens to you then this is a smooth process. Your mind is filled with repetitive stimulus from all your senses every day but it's just filtered out (like the feeling in your big toe as you read this....)
If the stimulus is harmful then the filtering is a long hard process for obvious reasons, your ancestors who found it easy to ignore usually got killed for not dealing with the danger and their genes were weeded out of existence.
Doubly unfortunate is the fact that your conscious mind (PFC) also has feedback to your amygdala and constantly reminds it to be bothered by your T and it's a vicious circle.
To speed up habituation you literally have to "fake it till you make it" with the "it" being not caring about tinnitus, you're sending PFC assurances to the amygdala that all is well and to stop sticking emotional content onto the sound, eventually it does just that; attachments aren't affixed and the signal fits through the little hole back into the MGN for noise cancellation
.
Lots of people who are hard of hearing have no tinnitus and it's because it's so gradual that it gets through the amygdala undercover. Whereas a sudden loss like acoustic trauma is too big to ignore.
In your case the acoustic trauma got the amygdala out of bed and it started sticking attachments onto all the sound of your T and once the spike had subsided it's still there doing it to your original T. Stop worrying about it and it will only be there when you listen for it.
When you go to bed tonight remind your amygdala that LLLT and Autofoni are on there way so it can relax even more
Hope that makes sense. Regards Silvine