Objective: To investigate how tinnitus affects the processing of speech and non-speech stimuli at the subcortical level. Study Design: Cross-sectional analytical study. Setting: Academic, tertiary referral center. Patients: Eighteen individuals with tinnitus and 20 controls without tinnitus matched based on their age and sex. All subjects had normal hearing sensitivity. Intervention: Diagnostic. Main Outcome Measures: The effect of tinnitus on the parameters of auditory brainstem responses (ABR) to non-speech (click-ABR), and speech (sABR) stimuli was investigated. Results: Latencies of click ABR in waves III, V, and Vn, as well as inter-peak latency (IPL) of I to V were significantly longer in individuals with tinnitus compared with the controls. Individuals with tinnitus demonstrated significantly longer latencies of all sABR waves than the control group. The tinnitus patients also exhibited a significant decrease in the slope of the V-A complex and reduced encoding of the first and higher formants. A significant difference was observed between the two groups in the spectral magnitudes, the first formant frequency range (F1) and a higher frequency region (HF). Conclusions: Our findings suggest that maladaptive neural plasticity resulting from tinnitus can be subcortically measured and affects timing processing of both speech and non-speech stimuli. The findings have been discussed based on models of maladaptive plasticity and the interference of tinnitus as an internal noise in synthesizing speech auditory stimuli.

Objectives: Tinnitus is one of the most common otological symptoms in patients with temporomandibular disorders. This study aimed to investigate the possible association between tinnitus and temporomandibular disorders. Methods: The online databases of PubMed, Ovid, ScienceDirect, and Web of Science were explored for all English articles published until September 2018 using the combined keywords tinnitus and temporomandibular. Cross-sectional, cohort, or case-control studies that investigated the association between tinnitus and temporomandibular disorders (TMDs) were considered. The quality of the included papers was assessed by the Crowe Critical Appraisal Tool. Results: Twenty-two papers met the eligibility criteria and were included in the systematic review. Meta-analysis was performed on 8 papers to investigate the possible relationship between tinnitus and TMDs by calculating the odds ratios. Odds ratios ranged from 1.78 to 7.79 in the studies related to tinnitus frequency in temporomandibular disorders and from 1.80 to 7.79 in the papers linked to temporomandibular disorder frequency in tinnitus, indicating a significant association between tinnitus and temporomandibular disorders. Conclusions: There was a strong relationship between tinnitus occurrence and TMDs. The findings implied the significance of exploring the signs of TMDs in patients with tinnitus as well as tinnitus in those who complain from temporomandibular disorders.

Introduction:Tinnitus is one of the complex symptoms of hearing described as a phantom auditory sensation without any external stimulation. Due to the subjective nature of tinnitus, perception and discomfort of tinnitus vary among the patients. The main aim of this study is to investigate the effects of gender, age and the degree of hearing loss on discomfort due to tinnitus.Methods:Eighteen patients with tinnitus, aged 21–72 years, (9 males and 9 females) were recruited. Tinnitus discomfort was investigated by Tinnitus Handicap Inventory (THI) questionnaire. Psychoacoustic assessments of tinnitus and auditory threshold assessments were evaluated using a 2-channel clinical audiometer.Results:The results showed no significant correlation between THI scores with loudness matching (P=0.187), mean of auditory threshold (P=0.304), gender (P=0.93) and age (P=0.200). Also, no significant correlation was found between maximal level of hearing loss and pitch matching (P=0.208).Conclusion:The study findings suggests that tinnitus is not correlated with age, gender and hearing loss. Overall, tinnitus is a complicated clinical condition which its real impact and degree of discomfort are unclear. More investigation is needed to clarify the factors involving in tinnitus annoyance.

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