Speech prostheses

Speech prostheses, or voice prostheses, is a overall term for small, silicon one-way valves that are inserted into the tracheoesophageal puncture of laryngectomy patients. The prosthesis not only safely divides the oesophagus and trachea, but also allow speech when the outside of the stoma, the opening on the neck to allow air in, is covered with a finger or otherwise occluded. This is greatly beneficial to patients because it allows to communicate without the need to use either an Electrolarynx or Speech synthesizers.

https://www.inhealth.com/category_s/44.htm

http://www.cancerresearchuk.org/about-cancer/type/larynx-cancer/living/stoma/starting-out-with-a-breathing-stoma

http://www.webwhispers.org/library/tepprosthesis.asp

https://en.wikipedia.org/wiki/Voice_prosthesis

http://medind.nic.in/jat/t07/i4/jatt07i4p188.htm

Main characteristics

Oesophageal valves are made of silicon and primarily consists of four parts.