COMPARISON FOR SPEECH CODING ALGORITHMS FOR TOTAL LARYNGECTOMIES

Electrolarynx is used as a noninvasive supporting device for speech restoration in people who have undergone resection operation over their larynxes. This work aims to develop a signal processing method to neutralize the mechanical vibration noise of this device. We investigate the effect of this noise on the speech signal and analyze the performances of various algorithms in a single input system to minimize this noise

Augmented control of hands free voice prostheses

Laryngectomy patients often use an electrolarynx to facilitate speech following a tracheotomy. Devices of this type provide the most intelligible means of communication for tracheotomy patients. However, the electro-larynx has inherent drawbacks such as the buzzing monotonic sound emitted, the need for a free hand to operate the device, and the difficulty experienced by many tracheotomy patients in adapting to use it. The most effective means of addressing the shortcomings of existing electro-larynges is to provide the user with a hands-free facility. This allows the user to perform other manual tasks whilst speaking, or simply to communicate more effectively through body language. Hands-free devices do exist but require a considerable amount of patient training as they involve the use of the shoulder muscles to control pitch. Furthermore, they are not suitable for all patients as the hands-free is suitable only for users with a certain type of tracheotomy. Goldstein et al in 2004 [1] produced a working prototype of a hands-free device that employed electromyographic signals to activate the device. However, it was quite cumbersome in design and failed to alleviate the monotonous sound produced. The goal of this research is to research the implementation of a hands-free electrolarynx, using various activation methods including electromyographic signals to vary parameters of the output signal. Once a satisfactory system of initiation has been devised and tested, a method of pitch variation shall be developed

Intelligibility of Electrolarynx Speech using a Novel Hands-Free Actuator

During voiced speech, the larynx provides quasi-periodic acoustic excitation of the vocal tract. In most electrolarynxes, mechanical vibrations are produced by a linear electromechanical actuator, the armature of which percusses against a metal or plastic plate at a frequency within the range of glottal excitation. In this paper, the intelligibility of speech produced using a novel hands-free actuator is compared to speech produced using a conventional electrolarynx. Two able-bodied speakers (one male, one female) performed a closed response test containing 28 monosyllabic words, once using a conventional electrolarynx and a second time using the novel design. The resulting audio recordings were randomized and replayed to ten listeners who recorded each word that they heard. The results show that the speech produced using the hands-free actuator was substantially more intelligible to the majority of listeners than that produced using the conventional electrolarynx. The new actuator has properties (size, weight, shape, cost) which lends itself as a suitable candidate for possible hands-free operation. This is one of the research ideals for the group and this test methodology presented as a means of testing intelligibility. This paper outlines the procedure for the possible testing of intelligibility of electrolarynx designs

Consideraciones generales acerca del uso de la laringe eléctrica en la reeducación logopédica de un laringectomizado

The aim of this paper is to spread the use of the electrolarynx as one of the methods used within the context of voice therapygiven to a person who has lost the larynx and therefore the ability to communicate orally, with the role of the voice pathologyspecialist being decisive the in improving the quality of life for cancer patientsEl objetivo del presente artículo es difundir el uso de la laringe eléctrica como uno de los métodos usados dentro del contexto dela reeducación logopédica a la que va a ser sometido a la persona que ha perdido la laringe y por ende la capacidad paracomunicarse oralmente. Siendo el rol de la especialista en patología vocal determinante para mejorar la calidad de vida delpaciente oncológic

The Application of Clear Speech in Electrolaryngeal Speakers

The present work was comprised of a series of experiments that investigated the application of clear speech (CS) in a group of electrolaryngeal (EL) speakers. Three experiments were conducted to assess the impact of CS on three important aspects of EL speech. More specifically, Experiment 1 sought to identify the impact of CS on EL speakers’ word and consonant intelligibility; Experiment 2 examined the influence of CS on the acoustic characteristics of words and vowels in EL speech; and finally, Experiment 3 sought to identify the influence of CS produced by EL speakers on auditory-perceptual ratings by naïve listeners. Results revealed that overall word and consonant intelligibility were minimally different when EL speakers used CS compared to their everyday, ‘habitual’ speech (HS) (Experiment 1). Secondly, EL speakers’ use of CS significantly increased word durations, but did not have a substantial impact on fundamental and formant frequency characteristics of vowels (Experiment 2). Finally, due to the productive changes associated with CS involving a slower rate of speech, over-articulation, and increased mouth-opening, listeners judged EL speech to be significantly less acceptable to listen to when compared to HS. However, no significant effect of speaking condition was noted on listeners’ comfort levels (Experiment 3). Overall, findings suggest that the acoustic deficits in EL speech might be too complex to derive further benefit from CS in the areas of speech intelligibility, the acoustic structure of EL speech and/or auditory-perceptual ratings of EL speakers. Clinical implications and future directions for research are discussed

The Application of Nonlinear Spectral Subtraction Method on Millimeter Wave Conducted Speech Enhancement

A nonlinear multiband spectral subtraction method is investigated in this study to reduce the colored electronic noise in millimeter wave (MMW) radar conducted speech. Because the over-subtraction factor of each Bark frequency band can be adaptively adjusted, the nonuniform effects of colored noise in the spectrum of the MMW radar speech can be taken into account in the enhancement process. Both the results of the time-frequency distribution analysis and perceptual evaluation test suggest that a better whole-frequency noise reduction effect is obtained, and the perceptually annoying musical noise was efficiently reduced, with little distortion to speech information as compared to the other standard speech enhancement algorithm

Perceptual and acoustic impacts of aberrant properties of electrolaryngeal speech.

Thesis (Ph. D.)—Harvard-MIT Division of Health Sciences and Technology, 2003.Includes bibliographical references (p. 167-171).This electronic version was prepared by the author. The certified thesis is available in the Institute Archives and Special Collections.Ph. D

Em direcção a uma laringe artificial electrónica : fundamentos técnico-científicos e ensaios preliminares

Tese de mestrado. Engenharia Biomédia (Área de Especialização de Sinais e Imagens Médicas). Faculdade de Engenharia. Universidade do Porto, Faculdade de Medicina. Universidade do Porto. 200

Reconstruction of intelligible audio speech from visual speech information

The aim of the work conducted in this thesis is to reconstruct audio speech signals using information which can be extracted solely from a visual stream of a speaker's face, with application for surveillance scenarios and silent speech interfaces. Visual speech is limited to that which can be seen of the mouth, lips, teeth, and tongue, where the visual articulators convey considerably less information than in the audio domain, leading to the task being difficult. Accordingly, the emphasis is on the reconstruction of intelligible speech, with less regard given to quality. A speech production model is used to reconstruct audio speech, where methods are presented in this work for generating or estimating the necessary parameters for the model. Three approaches are explored for producing spectral-envelope estimates from visual features as this parameter provides the greatest contribution to speech intelligibility. The first approach uses regression to perform the visual-to-audio mapping, and then two further approaches are explored using vector quantisation techniques and classification models, with long-range temporal information incorporated at the feature and model-level. Excitation information, namely fundamental frequency and aperiodicity, is generated using artificial methods and joint-feature clustering approaches. Evaluations are first performed using mean squared error analyses and objective measures of speech intelligibility to refine the various system configurations, and then subjective listening tests are conducted to determine word-level accuracy, giving real intelligibility scores, of reconstructed speech. The best performing visual-to-audio domain mapping approach, using a clustering-and-classification framework with feature-level temporal encoding, is able to achieve audio-only intelligibility scores of 77 %, and audiovisual intelligibility scores of 84 %, on the GRID dataset. Furthermore, the methods are applied to a larger and more continuous dataset, with less favourable results, but with the belief that extensions to the work presented will yield a further increase in intelligibility