Studies from independent labs demonstrated alterations in CN neural activity that were correlated with tinnitus behavior but not with changes in auditory brain stem response (ABR) thresholds or supra threshold ABR wave-1 amplitude (i.e., ABR responses to increasing levels of intensity) (Li et al., 2015; Wu et al., 2016).

References: 1) Li S, Kalappa BI, Tzounopoulos T. Noise-induced plasticity of KCNQ2/3 and HCN channels underlies vulnerability and resilience to tinnitus. Elife. 2015 Aug 27;4:e07242. doi: 10.7554/eLife.07242. PMID: 26312501; PMCID: PMC4592936. 2) Wu C, Martel DT, Shore SE. Increased Synchrony and Bursting of Dorsal Cochlear Nucleus Fusiform Cells Correlate with Tinnitus. J Neurosci. 2016 Feb 10;36(6):2068-73. doi: 10.1523/JNEUROSCI.3960-15.2016. PMID: 26865628; PMCID: PMC4748084.

Tinnitus results from changes within the auditory system, which may stem from damage to the ear or the neural pathways that carry sound to the brain. The most accepted theory is that tinnitus comes from outer hair cell damage in the cochlea in the ear, leading to changes in the signals sent from the ear to the brain. Some research suggests that when these normal signals are disrupted, the brain compensates by creating its own noise, leading to tinnitus. This phantom sound can also emerge as the brain’s auditory system becomes overly sensitive after hearing loss, detecting internal processes in the ear and interpreting them as sound. Further research indicates that tinnitus is associated with changes in the brain’s activity pattern, suggesting it’s not just a hearing issue but also involves significant neuroplastic changes within the brain’s auditory cortex (“Understanding the Facts,” American Tinnitus Association).

Source: American Tinnitus Association – Understanding the Facts

Tinnitus is the perception of noise or ringing in the ears, a common condition affecting about 15% to 20% of people. It is not a condition itself but rather a symptom of an underlying condition, such as age-related hearing loss, ear injury, or a circulatory system disorder. Tinnitus can vary in pitch from a low roar to a high squeal, and you may hear it in one or both ears. In some cases, the sound can be so loud it can interfere with your ability to concentrate or hear external sound. Tinnitus may be present all the time, or it may come and go. Despite extensive research, tinnitus remains a poorly understood condition with no cure, but there are several treatments available to help manage its symptoms (“Tinnitus,” Mayo Clinic). 

Source: Tinnitus, Mayo Clinic