Modeling of the effect of negative pressure difference between ear canal and middle ear using a Young’s modulus of E = 100 MPa. Left: Acoustic input impedance at the eardrum Z_D and eardrum acoustic shunt impedance Z_ac for different pressure differences Δp₀ in kPa between ear canal and middle ear. Right: Ear canal impedance for different pressure differences Δp₀ in kPa resulting from the model using an ear canal radius of 1.7 mm and an ear canal length of 14 mm, together with ear canal impedances from [7] measured in infants’ ears where the tympanometric peak pressure was smaller −1 kPa (−100 daPa).