IMPROVED LABORATORY PROTOTYPE ELECTROLARYNX (LAPEL) - USING INVERSE FILTERING OF THE FREQUENCY-RESPONSE FUNCTION OF THE HUMAN THROAT

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.