title: Voluntarily retractable tympanic membranes: case report.
abstract: A very rare case of a 7-year-old boy, who was in the habit of voluntarily controlling his hearing acuity by bilaterally retracting his tympanic membranes, is reported. Although normal A type tympanograms were initially observed, B type tympanograms and a decrease in hearing acuity to a hearing level of 35 dB on both sides was seen when he sniffed with both nostrils pinched (the reverse Valsalva maneuver). The patient would repeat the action on such occasions as when he wanted to concentrate on playing computer games while his mother was watching TV with the volume up, while he was swimming, or when the surroundings were noisy between lessons at school. When he wanted to normalize hearing, he would adjust the position of the tympanic membranes by performing the Valsalva maneuver. The patient probably had incomplete closure of the eustachian tube. The eustachian tube could be locked by high negative middle ear pressure induced by the reverse Valsalva maneuver, which resulted in a decrease of hearing acuity caused by retraction of the tympanic membranes bilaterally.
authors.affiliation: Department of Otorhinolaryngology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: T
authors.initials: T
authors.lastname: Takasaka
mesh_terms: D000158:Acoustic Impedance Tests; D002648:Child; D006309:Hearing / Q000502:physiology*; D006801:Humans; D008297:Male; D014432:Tympanic Membrane / Q000502:physiology*