system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Phonation in oesophageal speech in a case of laryngectomy is produced by:
assistant
The correct answer is  In a normal person phonation is produced by vocal cords which vibrate in response of force of air produced by lungs. In oesophageal speech, patient "inhales" air into the oesophagus and then ejects it by the contraction of chest muscles. Pharyngo-oesophageal segment functions for the missing vocal cords and vibrates to produce phonation. Since only limited amount of air can be ejected from the oesophagus, maximum phonatorv time is short and patient can speak only a few words.