Speech prostheses

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