The Comparison of the Comodulation Masking Release (CMR) in Individuals with and without Chronic Tinnitus

Publication date: Available online 9 April 2019Source: Neuroscience LettersAuthor(s): Leila Faraji, Akram Pourbakht, Hamid HaghaniAbstractIn comodulation masking release (CMR), the auditory signal threshold improves when maskers far from the frequency of the target signal are coherently amplitude-modulated. Studies show that inhibitory function may play a role in CMR. In individuals who have tinnitus, decreasing inhibitory functioning in auditory central nervous system has been documented. Therefore, in this study, the purpose was to evaluate CMR in individuals suffering from tinnitus and compare CMR findings with those who do not have tinnitus. Seventeen normal-hearing individuals (without tinnitus) and 13 individuals having unilateral tonal tinnitus (4000 or 6000 Hz) with normal or near to normal hearing participated in this study. All participants were 20 to 50 years of age and underwent comodulated (CM), unmodulated (UM), and reference (RF) threshold measurements and then the CMRs (CMR and Across Frequency CMR; AF-CMR) were calculated. An ANOVA showed that the CM thresholds were statistically different between groups, while the RF and UM thresholds were not statistically different. CMR (CMR & AF-CMR) function was higher in those without tinnitus compared to unilateral tinnitus sufferers. Due to the inhibitory role of the auditory central nervous system in CMR, it appears that tinnitus and CMR both may be influenced by inhibitory function.
Source: Neuroscience Letters - Category: Neuroscience Source Type: research