[The study of the modification of the natural resonance of the external ear following tympanoplasty].

The shape, position and amplitude of the natural resonance curve of external ear is related to sensation evoked in a subject by sound coming from the external environment. The involution of this curve varies from individual and is the sum of the effects provoked on the incident sound by the head, auricle and the conformation of canal (EEE = External Ear Effect). Natural amplification supplied by the system allows the individual to distinguish natural sound, whose being natural make them pleasant to hear. Any interventions that modifies the anatomy of the auricle and/or the canal activity alternates the REUR (Real Ear Unaided Response) to some degree. Restoration of basic anatomical conditions are choice of interventions which displace the curve only slightly allows a physiological sensation of sound to be maintained. Surgeon often neglect this little studied aspect preferring to evaluate this work in terms of quantity thus rather ignoring the quality of sound achieved.