I've often wondered about this too. From what I've read it seems that crystals being dislodged from the ear or thyroid issues lead to a roaring sound, while drug-induced leads to a high pitched sound for certain medications at least...
One thing that would be really neat is if we could harness the size of TT to conduct some survey research on type of tinnitus (what it sounds like, how loud, somatic/reactive/present with hearing loss etc), presumed cause, demographic characteristics like Age Country of residence Ethnicity, and whether habituation or remission of symptoms occurred. With almost 29,000 members even if 1 in 10 responded that is still a significant amount of data... There could even be an option for individuals to anonymously upload their 23andme/promethease results giving us biomarker data to sift through... Of course, the t population here is likely biased towards more severe sufferers but it would still be extremely valuable and I'm not sure it's ever been done before. Although not a cure, this could potentially provide answers to questions such as "Do younger individuals have better recovery from acoustic trauma versus older individuals", "Does noise-induced tinnitus sound different than drug-induced tinnitus", "How significant is the genetic component for developing tinnitus and which genes are most associated". Genome-wide association studies are done for so many diseases, why not tinnitus??
Also from an epidemiological perspective, I've noticed that on this message board individuals from Northern European countries are overrepresented versus Asian or Latin American Countries (or maybe they just post more since this is an English speaking board). But another question that I've wondered is, do certain countries have less or more incidence of tinnitus and could that be due to latitude (sun exposure, weather, etc), diet, etc.
Tagging
@Hazel @markuu as these are some ideas for the next survey (if there is one)
Honestly one of the biggest mistakes people make about tinnitus is lumping together different subtypes.
What makes tinnitus so difficult to solve is its 'heterogeneity.' It may all fall in the same basket but tinnitus has vast variety as reflected anecdotally on this board.
If you get a chance, watch the video I linked above and if time permits, watch it twice because there so much information explaining the complexity of tinnitus, best to watch it a second time to further absorb this rather complex subject matter. The scope of tinnitus is considerable.
In particular because each of our brains are organized differently, tinnitus will likely not occupy precisely the same regions for any two people. The permutations are literally mind blowing forgive the pun.
I am a good example and of course when I watched the video I did so based upon my particular vantage point...consideration of my particular tinnitus subtype.
There is a large tinnitus subtype on this forum whereby sleep dramatically affects their tinnitus. Sleep is the overwhelming trigger for my tinnitus. Why would this be? One theory is...I dream vividly and can recollect many of my dreams if focused upon them as I wake which is many times accompanied by a raging hiss. My audiologist who may not be an expert in tinnitus, believes its elevated cortisol levels. My comment would be...cortisol is a possible contributor but I believe there is more to it and touched upon in the video.
If you listen to the professor in the video, he discusses different regions of the brain specific to brain 'frequency' which relates to dream versus awake brain wave activity which can even be affected by cross communication of these regions. This further explains why myself and many others who change brain waves and frequency...why this dramatically influences our tinnitus...because their (my) tinnitus lives or is amplified by these regions of the brain being active in the dream state and more dormant in the awake state as I type this where brain activity is much different.
If you watch the video with an eye toward brain frequency and region and brain wave activity as the professor explains....how people can have very different areas of the brain affecting their tinnitus due to the organization of an individual's brain, I believe it becomes more clear just how complex tinnitus is and why all subtypes can't be lumped together. Tinnitus is a brain disorder and our brains many times are organized very differently which can be applied crudely to a particular subtype. Truth is, subtypes are likely multivariant as well.
Many like me here can take a 30 minute nap or fall into a deep sleep with related brain wave change which can send their tinnitus to obtrusive sound level as they wake. This happens all the time with me. Pretty clear, my tinnitus is a function of brain wave activity and regions of the brain affected by this change in frequency as I sleep which are more dormant when awake as my tinnitus is generally lower when awake for a period of time.
The following link addresses the various brain wave tiers relative to frequency which relate to location within the brain.
https://blog.mindvalley.com/brain-waves/
Another conversation relates to mental health and tinnitus and I believe there is a high correlation between anxiety, depression, OCD and other mental health deficits which affect neuron transmission and predisposition to 'remember' tinnitus long term. This may loosely correlate with brain organization...common among those prone to say OCD that Lane spoke of which may relate to 'chemistry' of the brain and organization and even hemisphere dominance.
In summary there are an incalculable number of subtypes of varying degrees.
I believe it will be a long spiral staircase of learning to better define tinnitus subtypes well into the future.
If the tinnitus signal can be 'confounded' by bi-modal stimulation breaking up the synchronicity of hyperactive fusiform cells localized in the brain stem...which is the conduit of communication with the auditory cortex creating tinnitus...independent of different regions of the brain firing based upon brain frequency, then we win. My hope for all.