الفهرس 
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Abstract
Tinnitus is defined as an auditory stimulus that is unrelated to external stimulation. Tinnitus can have a severe negative impact on quality of life. It may be the first or the most prominent symptom of various diseases that threaten the patient’s physical health and well-being. Different hypothesis were assumed for generation of tinnitus. Outer hair cell damage is believed to be involved in the development of peripheral tinnitus in individuals with normal hearing sensitivity. This study was done to evaluate extended high frequency audiometry and distortion product OAEs in tinnitus patients with normal hearing in comparison to normal hearing subjects not complaining of tinnitus. Study group was further subdivided according to tinnitus pitch matching into: Low and High Pitched tinnitus groups. The data of this study showed that patients with normal hearing sensitivity in the conventional frequency range (up to 8 kHz), and reporting tinnitus, present alterations of the auditory system in the affected side, manifested as elevated EHF thresholds at 9000, 10000, 11200,14000,16000 Hz. most tinnitus patients had pitch matching frequency at high frequency range between (3000-8000 Hz). As regard OAE the amplitude of TEOAE&DPOAE was lower in tinnitus patients relative to controls suggesting that subclinical cochlear impairment in limited areas may exist in tinnitus ears. Accordingly, DPOAE can present a frequency specific measurements for the detection of subtle localized cochlear damage even before affecting pure tone thresholds.Hence, DPOAE combined with behavioral EHF hearing thresholds may provide additional clinical information about the status of the peripheral hearingin tinnitus with normal hearing subjects.