Advanced Biomedical Engineering
Online ISSN : 2187-5219
ISSN-L : 2187-5219
Hands-Free Wearable Electrolarynx using Linear Predictive Coding Residual Waves and Listening Evaluation
Masaki TakeuchiJaesol AhnKunhak LeeKen TakakiTohru IfukubeKen-ichiro YabuShinnosuke TakamichiRumi UehaMasaki Sekino
Author information

2022 Volume 11 Pages 68-75


A conventional electrolarynx (EL), which is used by laryngectomees, produces monotonous sound and occupies a user's hand; hence, we developed a hands-free wearable device that improves voice quality. The proposed device estimates individual vocal tract features using linear predictive coding (LPC) and generates sound vibrations using an LPC inverse filter. Additionally, we reproduced the vibration sound using a transducer and amplified the first harmonic frequency and the second one. We conducted an objective experiment to compare the spectra of natural voice, a conventional EL, and the proposed device. We also conducted a subjective experiment in which we asked healthy subjects to listen to and evaluate the conventional EL and the proposed device. The results of the objective experiment demonstrated that our model was characterized by two formant peaks that were similar to the conventional EL and the natural voice. The results of the subjective experiment demonstrated that our model was more powerful and clearer than the conventional EL. These findings indicate that the voice of our device is spectrally close to human voice and gives the audience a more powerful and clearer sound.

Content from these authors
© 2022 Japanese Society for Medical and Biological Engineering

Copyright: ©2022 The Author(s). This is an open access article distributed under the terms of the Creative Commons BY 4.0 International (Attribution) License (, which permits the unrestricted distribution, reproduction and use of the article provided the original source and authors are credited.
Previous article Next article