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The normal functioning of the larynx or voicebox gives humans the ability to converse with others effortlessly. However, if the larynx is permanently removed due to injury or illness, speech cannot be produced. The electrolarynx, a noninvasive device used to produce speech for such persons, has a motor-induced hum which hinders telephone-based communication among electrolaryngeal speakers. This adversely affects the morale of electrolarynx users, leading to abandonment of technology, psychological issues and decreased quality of life. This paper examines a technique based on bandpass filtering of electrolaryngeal speech which has the potential of increasing the quality and intelligibility of speech produced by means of an electrolarynx. Finite impulse response and infinite impulse response filtering with bandpass frequencies analogous to telephone landline and wideband filtering were investigated. Objective testing and subjective testing of quality and intelligibility of electrolaryngeal speech have been performed in each phase of the work. Statistical analysis based on one-way analysis of variance (ANOVA) has been conducted after each round of subjective testing. Results indicate that the quality as well as intelligibility of electrolaryngeal speech can be improved with the help of bandpass filtering. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this article is to discuss in detail an innovative student project that was developed for a graduate-level course in medical speech-language pathology. Method: Each student was provided with an artificial larynx (AL) for 1–2 weeks and completed various practice activities. Students then gave oral presentations demonstrating AL proficiency and discussing their experiences as an AL user. Conclusion: Overall, most students report enjoying the project and learning a great deal, especially regarding developing a sense of empathy toward laryngectomees. [ABSTRACT FROM AUTHOR]

Summary: In normal speech, coordinated activities of intrinsic laryngeal muscles suspend a glottal sound at utterance of voiceless consonants, automatically realizing a voicing control. In electrolaryngeal speech, however, the lack of voicing control is one of the causes of unclear voice, voiceless consonants tending to be misheard as the corresponding voiced consonants. In the present work, we developed an intra-oral vibrator with an intra-oral pressure sensor that detected utterance of voiceless phonemes during the intra-oral electrolaryngeal speech, and demonstrated that an intra-oral pressure–based voicing control could improve the intelligibility of the speech. The test voices were obtained from one electrolaryngeal speaker and one normal speaker. We first investigated on the speech analysis software how a voice onset time (VOT) and first formant (F 1) transition of the test consonant-vowel syllables contributed to voiceless/voiced contrasts, and developed an adequate voicing control strategy. We then compared the intelligibility of consonant-vowel syllables among the intra-oral electrolaryngeal speech with and without online voicing control. The increase of intra-oral pressure, typically with a peak ranging from 10 to 50gf/cm2, could reliably identify utterance of voiceless consonants. The speech analysis and intelligibility test then demonstrated that a short VOT caused the misidentification of the voiced consonants due to a clear F 1 transition. Finally, taking these results together, the online voicing control, which suspended the prosthetic tone while the intra-oral pressure exceeded 2.5gf/cm2 and during the 35milliseconds that followed, proved efficient to improve the voiceless/voiced contrast. [Copyright &y& Elsevier]

Summary: Objective: To realize an accurate and automatic on/off control of electrolarynx (EL), an artificial neural network (ANN) was introduced for switch identification based on visual information of lips and implemented by an experimental system (ANN-EL). The objective was to confirm the feasibility of the ANN method and evaluate the performance of ANN-EL in Mandarin speech. Study Design and Methods: Totally five volunteers (one laryngectomee and four normal speakers) participated in the whole process of experiments. First, trained ANN was tested to assess switch identification performance of ANN method. Then, voice initiation/termination time, speech fluency, and word intelligibility were measured and compared with button-EL and video-EL to evaluate on/off control performance of ANN-EL. Results: The test showed that ANN method performed accurate switch identification (>99%). ANN-EL was as fast as normal voice and button-EL in onset control, but a little slower in offset control. ANN-EL could provide a fluent voice source with rare breaks (<1%) for a continuous speech. The results also indicated that on/off control performance of ANN-EL had a significant impact on perception, lowering the word intelligibility compared with button-EL. However, the words produced by ANN-EL were more intelligible than video-EL by approximately 20%. Conclusions: The ANN method was proved feasible and effective for switch identification based on visual information of lips. The ANN-EL could provide an accurate on/off control for fluent Mandarin speech. [Copyright &y& Elsevier]

Summary: Objectives: To reduce the inconvenience caused by operating a button-electrolarynx (EL) by hand, we proposed a method for the automatic control of an EL via lip deformation and applied the method to a video-based experimental system (video-EL). The purpose of this study was to validate the method and assess its performance in producing Mandarin Chinese. Study Design and Methods: Eight subjects, including one laryngectomee, were invited to participate in the assessment. First, the empirical parameters of phonation onset/offset estimation were compared with the optimal parameters obtained by minimizing simulation errors during video-EL. Second, a reaction time test was used to evaluate the ability of subjects to pronounce a single word with video-EL. Third, the fluency of subjects in producing long sentences with video-EL was calculated. Finally, the intelligibility of speech produced with video-EL was compared with that produced with button-EL. Results: The empirical parameters were not significantly different from the optimal parameter and resulted in fewer interruptions during voicing. Video-EL resulted in slower voice initiation and termination when compared with button-EL, which affected the intelligibility of an isolated word. However, video-EL provided a sufficiently fluent voice source so that the intelligibility of speech produced with video-EL was not significantly different from speech produced with button-EL when producing sentences. Conclusions: The method proposed in this study is effective in the automatic on/off control of an EL. Subjects produced fluent speech with video-EL that was as intelligible as that produced with button-EL when Mandarin sentences were produced continuously. [Copyright &y& Elsevier]