title: In vitro evaluation of a double-membrane-based voice-producing element for laryngectomized patients.
abstract: BACKGROUND
  A sound generator based on a double-membrane design that fits into a regular tracheoesophageal shunt valve may improve voice quality after total laryngectomy in patients rehabilitated with surgical voice prostheses.
  
  
  METHODS
  Voice-producing element (VPE) prototypes were manufactured using medical grade biocompatible materials and tested in vitro under physiological conditions.
  
  
  RESULTS
  Basic sound, containing multiple harmonics, was successfully produced under physiologic air pressure and airflow conditions. The fundamental frequency and sound pressure level (SPL) is controlled by changing the driving pressure, thus enabling sufficient intonation for day-to-day speech. The obtained frequency range (190-350 Hz) is appropriate for producing a female voice. The low noise-to-harmonics ratio (mean 0.15) and also the efficiency of sound production (5.5 x 10(-5) at 80 dB(A) and 0.15 m microphone distance) is comparable to that of normal vocal folds.
  
  
  CONCLUSIONS
  Functional restoration of the voice after laryngectomy with a double-membrane VPE appears to be a feasible concept for female laryngectomized patients with a hypotonic, or atonic pharyngoesophageal segment.
authors.affiliation: Department of BioMedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, 9713 AV Groningen, the Netherlands.
authors.forename: Johannes W
authors.initials: JW
authors.lastname: Tack
authors.forename: Gerhard
authors.initials: G
authors.lastname: Rakhorst
authors.forename: Eduard B
authors.initials: EB
authors.lastname: van der Houwen
authors.forename: Hans F
authors.initials: HF
authors.lastname: Mahieu
authors.forename: Gijsbertus J
authors.initials: GJ
authors.lastname: Verkerke
mesh_terms: D000399:Air Pressure; D006801:Humans; D066298:In Vitro Techniques; D007825:Laryngectomy; D007831:Larynx, Artificial; D008422:Materials Testing; D008954:Models, Biological; D011474:Prosthesis Design; D013061:Speech Acoustics; D013068:Speech Production Measurement / Q000295:instrumentation; D013071:Speech, Alaryngeal / Q000295:instrumentation*; D014833:Voice Quality