Auditory and Vestibular Research Tehran University of Medical Sciences en-US Auditory and Vestibular Research 2423-480X <p><strong>Copyright and Conflict of Interest<br /> </strong>All submitted manuscripts should be accompanied with a statement from the author, showing there is no conflict of interest regarding that article. A conflict of interest, here, is a situation in which a medical research scientist, has competing professional or personal interests that make it difficult to fulfill his duties fairly. A conflict of interest can exist even if no unethical or improper act results from it, and can create an appearance of impropriety that can undermine confidence in the person or profession.<br /> The right is reserved for the journal to accept or reject the submitted article or incorporate any changes deemed necessary by the editorial board to make contributions harmonize the editorial standards of the journal.<br /> Accepted papers become the permanent property of Auditory and Vestibular Research.<br /> The act of submitting a manuscript to the journal carries with it the right to publish that paper and implies the transfer of the copyright from the author to the Publisher.</p> Morphology variations of click-evoked auditory brainstem response with low and high rate stimuli in rat <p><strong>Background and Aim:</strong> The auditory brainstem response (ABR) is one of the most common objective hearing tests conducting in animal and human. The purpose of this study was evaluating the morphology variations of ABR waveforms in rats with low and high rate click stimuli.<br> <strong>Methods:</strong> First, rats with ABR thresholds higher than 55 dB SPL were excluded and total 81 ears remained in study. Absolute and interpeak latencies of wave I, II, IV were evaluated at low (17.7 Hz) and high rate (88.7 Hz) for click stimuli at 120 dB SPL.<br> <strong>Results:</strong> At low rate stimuli, ABR waveforms showed different morphologies. The most com­mon complex for waves II to IV was wave III placed on downward slope of wave II (71% of cases). Almost the same morphologies were seen at higher rate; but in some waves, it rounded and decreased amplitude. For waves IV-V, the most common morphology was equal amplitude of wave IV and V in low and high rates (35% vs 56%, respectively). Generally, the high rate stimuli didn’t severely change morphology patterns except for later waves.<br> <strong>Conclusion:</strong> Normal click-evoked ABR could result in different waveforms. Using click stimuli at low and high rate result in different morphology patterns. Recognizing morphology variations of ABR waveforms are essential for detecting any pathological conditions. The high rate stimuli increased latencies, especially for later waves.</p> Sadegh Jafarzadeh Akram Pourbakht ##submission.copyrightStatement## 2018-10-10 2018-10-10