Rl. Norton et Rs. Bernstein, IMPROVED LABORATORY PROTOTYPE ELECTROLARYNX (LAPEL) - USING INVERSE FILTERING OF THE FREQUENCY-RESPONSE FUNCTION OF THE HUMAN THROAT, Annals of biomedical engineering, 21(2), 1993, pp. 163-174
The electrolarynx (EL) provides a valued means of verbal communication
for people who have lost their larynx. Existing ELs have some drawbac
ks such as harsh, raucous, and unpleasant sound and the presence of ba
ckground noise. This study presents an experimental analysis of two co
mmercial ELs and describes the development and testing of an improved
LAboratory Prototype ELectrolarynx (LAPEL) which more accurately simul
ates the sound of a natural larynx and has lower background noise. Thi
s natural sound is obtained by determining the frequency response func
tion (FRF) of the tissue of the human neck and using this information
to tailor the input signal to the EL by inverse filtering such that it
s output spectrum resembles that of the natural larynx. The result was
subjectively judged to have a superior and more natural sound than ex
isting electrolarynxes.