Signal Processing and Speech Communication Laboratory
hometheses & projects › Comparison of Excitation Signals for an Electronic Larynx

Comparison of Excitation Signals for an Electronic Larynx

Master Thesis
Announcement date
07 Jan 2008
Christian Jochum, Peter Reiner
Research Areas

Laryngectomees are a clinical population who, typically due to cancer, have their larynx surgically removed. As a result the patient has to live without vocal folds. One possible method to regain the ability to speak is the usage of an artificial electronic larynx (EL), which is a mechanical device that produces sound vibrations that are transmitted through the neck tissue into the vocal tract. Such EL-speech, is far from sounding natural, which results from the nonlinear transducer design of today’s available ELs and the very limited prosody.

In this thesis we examine a variety of sound signal generation approaches as potential speech source models, that could be used in a future EL, based on a linear transducer design, that is simulated in this thesis by an electrodynamic exciter. The speech quality resulting from the selected and implemented models is then evaluated by using a Comparison Category Rating (CCR), trying to explicitly assess the perceived frequency spectrum, the listening effort, the noise and the overall quality. The results indicate a improvement for some models in the naturalness of the produced speech which is in direct association with the perceived frequency spectrum.