Tehran University of Medical Sciences Auditory and Vestibular Research 2423-480X 23 3 2017 07 31 75 81 Minoo Karimi Department of Audiology, Faculty of Rehabilitation Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mohammad-Ebrahim Mahdavi-Zafarghandi Department of Audiology, Faculty of Rehabilitation Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran Homa Zarrinkoob Department of Audiology, Faculty of Rehabilitation Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mozhdeh Safavi Department of Audiology, Faculty of Rehabilitation Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran Seyyed Mehdi Tabatabaee Department of Biostatistics, Faculty of Rehabilitation Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2017 05 22 Background and Aim: It is not known how electrocochleography components of action potentials (AP) and summating potentials (SP) are changed in response to CE-chirp stimulus using extratympanic electrodes. This study was done for comparing summating potentials and action potentials specifications in response to CE-chirp and click stimuli. Methods: Electrocochleography components of action potentials and summating potentials were recorded in 16 normal hearing subjects (8 men and 8 women) aged 22-30 years (mean: 26.7 with SD 2.5 years) with audiometric (250-8000 Hz) hearing thresholds of 15 dB HL or better in response to click and CE-chirp stimulus at 90 dB nHL. Amplitude, duration, latency and area of summating potentials and action potentials and SP/AP amplitude and area ratios were compared. Results: Among the measured parameters, action potentials amplitude in response to CE-chirp stimulus (0.41 with SD 0.26 µV) was significantly smaller than action potentials amplitude in response to click (0.61 with SD 0.29 µV) stimulus (p<0.005). Relative frequency of detecting summating potentials in response to CE-chirp (68.7%) was lower than (100%) click (p<0.005). Conclusion: Recording electrocochleography component of summating potentials and action potentials with CE-chirp stimulus at high intensity level in normal hearing individuals shows no advantage over click stimulus. Small amplitude of summating potentials as a major problem of extratympanic electrocochleography cannot be solved using CE-chirp stimulus. https://avr.tums.ac.ir/index.php/avr/article/view/246