An Artificial Larynx Built in TE Shunt Valve That Produces Substitute Voice by Only Patient's Own Expiration (Preliminary Study for Suitable Tone Pitch and Its Controllability)

Abstract

A large portion of patients of larynx cancer tekes total laryngectomy and loses their original voice consequently. Some ways to obtain substitute voice for total laryngectomees have been presented, however, each of them cannot conquer inconveniences, tone quality, extremely low tone, monotonousness etc. We invented very simple, small enough to be built in TE (tracheaesophageal) shunt valve but functional substitute voice that is driven by patient's own expiration and its tone pitch can be controlled by expiratory pressure simultaneously. The new device has an outward-striking membrane as an oscillating valve and a set of piston-cylinder mechanism, which controls oscillator's tension and alters pitch of sound. As results of performance experiments applied to the prototype model made as twice scale as an actual dimension, the device produces the lowest sound frequency of 205 Hz and pitch range of 374 cent being approximately proportional to driving air pressure between 0.8 and 2.2 kPa. It is said that normal pitch of female voice is around 210 Hz, thus we consider the possibility of the device as a new substitute voice was shown that contributes to improvement of total laryngectomees' QOL particularly to female patients.

Keywords

• welfare engineering
• biomechanics
• sound and acoustics
• substitute voice
• artificial larynx
• and tracheoesophageal speech