title: Voluntary contraction of the tensor tympani muscle and its audiometric effects.
abstract: BACKGROUND
  The tensor tympani muscle is the largest muscle within the middle ear. Its voluntary contraction is a very unusual event. Only a few papers have documented its audiometric effects.
  
  
  OBJECTIVE
  To report an unusual case of voluntary tensor tympani muscle contraction and describe its audiometric effects.
  
  
  METHODS
  A 27-year-old man, who presented complaining of voluntarily evoked bilateral tinnitus, was found to be able to voluntarily contract the tensor tympani muscle in both ears simultaneously. Audiograms were performed under conditions of rest and maximal contraction of the tensor tympani muscle. The most remarkable effects were conductive hearing loss at lower frequencies and an increase in middle-ear impedance.
  
  
  CONCLUSIONS
  The importance of the tensor tympani muscle in middle-ear physiology remains unclear. It has been related to the attenuation of sounds produced during the mastication process. Voluntary control over the tensor tympani muscle is an extremely rare event. However, an understanding of the potential audiometric effects of its contraction could aid the diagnosis of hearing disorders.
authors.affiliation: Department of Otolaryngology, University Hospital, Universidade Luterana do Brasil, Canoas, Brazil.
authors.forename: R D
authors.initials: RD
authors.lastname: Angeli
authors.affiliation: Department of Otolaryngology, University Hospital, Universidade Luterana do Brasil, Canoas, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Lise
authors.affiliation: Department of Otolaryngology, University Hospital, Universidade Luterana do Brasil, Canoas, Brazil.
authors.forename: C C
authors.initials: CC
authors.lastname: Tabajara
authors.affiliation: Department of Otolaryngology, University Hospital, Universidade Luterana do Brasil, Canoas, Brazil.
authors.forename: T B
authors.initials: TB
authors.lastname: Maffacioli
mesh_terms: D000158:Acoustic Impedance Tests / Q000379:methods; D000328:Adult; D004432:Ear, Middle; D006314:Hearing Loss, Conductive / Q000209:etiology; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D013719:Tensor Tympani; D014012:Tinnitus / Q000175:diagnosis / Q000209:etiology*