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Each one of us perceives the sounds around us differently. The acoustic characteristics of the outer ear have a significant influence to the sensation of hearing. The tendency of the ear canal to shape the spectral structure of sounds has not been studied systematically and the role of the ear canal as a part of the outer ear is not yet completely known. Our research focused on scrutinizing the effects of varying physical dimensions of the outer ear and particularly those of the ear canal to the pressure at the eardrum. The main emphasis was on determining the influence of the length of the ear canal to the frequency response at the eardrum and thereby to the sensation of hearing. In addition, the eardrum’s damping of the resonance frequencies was studied

https://www.researchgate.net/publication/27516937_Measurement_Apparatus_and_Modelling_Techniques_of_Ear_Canal_Acoustics