A Korean study has shown that hearing thresholds were higher, the loudness of tinnitus was smaller and the degree of damage to the hair cells in the inner ear was lower in patients with presbycusis (age-related hearing loss) than in those with a noise-induced hearing loss.
Latencies in hearing were more prolonged in patients with presbycusis despite their lower hearing thresholds. These phenomena may reflect the effects of ageing or degeneration of the central nervous system with age, the authors write.
Facts about the study
The study examined 248 persons with chronic tinnitus from 2015 to 2020 with noise-induced hearing loss or presbycusis (age-related hearing loss).
In the study, people with noise-induced hearing loss were defined as those with a history of exposure to noise, such as workers in the mining and machinery industries with a hearing threshold of 25 dB or greater. People with presbycusis were defined as those aged 65 years or older without a history of noise exposure and with a hearing threshold of 25 dB or greater.
All patients with tinnitus were evaluated by tests of pure tone audiometry (PTA), auditory brainstem response (ABR), distortion product otoacoustic emissions (DPOAE) and transient evoked otoacoustic emissions (TEOAE). So called “Tinnitograms” were performed to get the pitch and loudness of tinnitus.
The study, "Analysis of Chronic Tinnitus in Noise-Induced Hearing Loss and Presbycusis", was published in the Journal of Clinical Medicine.
Sources: pubmed.ncbi.nlm.nih.gov and the Journal of Clinical Medicine