Objective assessment of subjective tinnitus through contralateral suppression of otoacoustic emissions by white noise: effects of frequency, gender, tinnitus bilaterality and age

Objective Detection of Tinnitus Based on Electrophysiology

Tinnitus, a common disease in the clinic, is associated with persistent pain and high costs to society. Several aspects of tinnitus, such as the pathophysiology mechanism, effective treatment, objective detection, etc., have not been elucidated. Any change in the auditory pathway can lead to tinnitus. At present, there is no clear and unified mechanism to explain tinnitus, and the hypotheses regarding its mechanism include auditory plasticity theory, cortical reorganization theory, dorsal cochlear nucleus hypothesis, etc. Current theories on the mechanism of tinnitus mainly focus on the abnormal activity of the central nervous system. Unfortunately, there is currently a lack of objective diagnostic methods for tinnitus. Developing a method that can detect tinnitus objectively is crucial, only in this way can we identify whether the patient really suffers from tinnitus in the case of cognitive impairment or medical disputes and the therapeutic effect of tinnitus. Electrophysiological investigations have prompted the development of an objective detection of tinnitus by potentials recorded in the auditory pathway. However, there is no objective indicator with sufficient sensitivity and specificity to diagnose tinnitus at present. Based on recent findings of studies with various methods, possible electrophysiological approaches to detect the presence of tinnitus have been summarized. We analyze the change of neural activity throughout the auditory pathway in tinnitus subjects and in patients with tinnitus of varying severity to find available parameters in these methods, which is helpful to further explore the feasibility of using electrophysiological methods for the objective detection of tinnitus.

Evaluation of medial olivocochlear efferent system and hearing loss in patients with primary Sjögren’s syndrome

Background/aim

Autoimmune diseases are a remarkable issue for researchers due to their adverse effects on the auditory system, but for primary Sjögren’s syndrome (pSS) there is little research on the comprehensive audiological findings in literature. The main objective of this study was to investigate the medial olivocochlear efferent functions of subjects with pSS and to examine the audiological findings.

Materials and methods

The study included 36 subjects with pSS and 36 healthy subjects. All the subjects underwent testing including pure tone, speech, and high frequency audiometry; tympanometry and acoustic reflexes; distortion product otoacoustic emissions (DPOAE); and suppression of DPOAE.

Results

The hearing thresholds of the pSS group were higher than those of the control at all frequencies (P < 0.001). Minimal to mild sensorineural hearing loss was observed in 52.77% of all the subjects with pSS. Additionally, all of the subjects had type A curve tympanograms, but the static compliances of the pSS group were lower and the acoustic reflex thresholds were higher than in the control (P < 0.001). In suppression levels of DPOAE, no statistically significant difference was found between the groups (P > 0.05).

Conclusion

The study indicates that because of obtaining normal suppression levels in DPOAE, the medial olivocochlear efferent system is functional in pSS. However, there is a need for more tests, including auditory brainstem response, to evaluate the afferent auditory system in pSS.