Multi-frequency tympanometry with assessment of resonant frequency and phase angle define the situation of balance between the mass and stiffness components of the tympano-ossicular system. This examination do contribute important clinical data that help for better differential diagnosis of conductive hearing loss in cases of abnormal otoscopic examination of the tympanic membrane and in middle ear diseases.The primary goal of this study was to evaluate additive tympanometric measures for distinguishing different four groups with chronic non suppurative middle ear diseases. Using indices derived from both standard and multi-frequency tympanometry and correlating these findings with those at surgery was our aim.The greater the value of admittancemeter of sound transimitted through the middle ear system ,the more the system will be affected by its mass component ,.while the smaller the value of admittance sound transimitted through middle ear system ,the more the system will be influenced by its high stiffness component One of the most significant parameters derived from multi-frequency tympanometry and to be borne in mind is the “resonant frequency”. Resonant frequency in normal subjects lies in a range from 800 to 1500 Hz (Cesare et al., 2000).Pathologies that lead to an increase in stiffness of the tympano-ossicular system show a much higher resonant frequency, and vice versa. Pathologies that lead to an increase in mass component often display lower resonant frequency.The measurement of resonant frequency together with other audiometric procedures give additional information to evaluate middle ear disorders. Significant differences were found between the four groups of ear with various affection of the tympanic membrane.Finally, the distinctive tympanometric parameters in “conventional and multi-frequency tympanometries” in the different four groups of study together with the associated clinical manifestations of the diseses were properly diagnostic as evident at surgery.