Improving the sound quality of an electronic voice box

The present project attempted to design the next generation electronic voice box by modifying the driving signal of the device. Two steps were involved in the project. The first step involved designing a working minishaker system using existing commercial miniature shaker system that functions similarly to an electrolarynx, but with variable driving signals (type and frequency). The second step involved carrying out perceptual experiments to examine listeners' intelligibility and acceptability of the voice produced with the minishaker system associated with different driving signals by both normal laryngeal speakers and laryngectomized speakers of Cantonese. Upon completion of the experiments, the five driving signals and the five driving frequencies that are associated with the highest acceptability scores were obtained. It is anticipated that the next generation electronic voice box should be designed based on these driving signals and frequencies should yield better and more natural sound quality.