Development of speech prostheses: current status and recent advances

This is an Accepted Manuscript of an article published by Taylor & Francis in Expert Review of Medical Devices on September, 2010, available online: http://www.tandfonline.com/10.1586/erd.10.34.Brain–computer interfaces (BCIs) have been developed over the past decade to restore communication to persons with severe paralysis. In the most severe cases of paralysis, known as locked-in syndrome, patients retain cognition and sensation, but are capable of only slight voluntary eye movements. For these patients, no standard communication method is available, although some can use BCIs to communicate by selecting letters or words on a computer. Recent research has sought to improve on existing techniques by using BCIs to create a direct prediction of speech utterances rather than to simply control a spelling device. Such methods are the first steps towards speech prostheses as they are intended to entirely replace the vocal apparatus of paralyzed users. This article outlines many well known methods for restoration of communication by BCI and illustrates the difference between spelling devices and direct speech prediction or speech prosthesis

Silent Speech Interfaces for Speech Restoration: A Review

This work was supported in part by the Agencia Estatal de Investigacion (AEI) under Grant PID2019-108040RB-C22/AEI/10.13039/501100011033. The work of Jose A. Gonzalez-Lopez was supported in part by the Spanish Ministry of Science, Innovation and Universities under Juan de la Cierva-Incorporation Fellowship (IJCI-2017-32926).This review summarises the status of silent speech interface (SSI) research. SSIs rely on non-acoustic biosignals generated by the human body during speech production to enable communication whenever normal verbal communication is not possible or not desirable. In this review, we focus on the first case and present latest SSI research aimed at providing new alternative and augmentative communication methods for persons with severe speech disorders. SSIs can employ a variety of biosignals to enable silent communication, such as electrophysiological recordings of neural activity, electromyographic (EMG) recordings of vocal tract movements or the direct tracking of articulator movements using imaging techniques. Depending on the disorder, some sensing techniques may be better suited than others to capture speech-related information. For instance, EMG and imaging techniques are well suited for laryngectomised patients, whose vocal tract remains almost intact but are unable to speak after the removal of the vocal folds, but fail for severely paralysed individuals. From the biosignals, SSIs decode the intended message, using automatic speech recognition or speech synthesis algorithms. Despite considerable advances in recent years, most present-day SSIs have only been validated in laboratory settings for healthy users. Thus, as discussed in this paper, a number of challenges remain to be addressed in future research before SSIs can be promoted to real-world applications. If these issues can be addressed successfully, future SSIs will improve the lives of persons with severe speech impairments by restoring their communication capabilities.Agencia Estatal de Investigacion (AEI) PID2019-108040RB-C22/AEI/10.13039/501100011033Spanish Ministry of Science, Innovation and Universities under Juan de la Cierva-Incorporation Fellowship IJCI-2017-3292

Evaluation of Speech in Maxillary defects and Its Correction using Palatography: An In-Vivo Study.

INTRODUCTION: Most of the literature review is on speech analysis and correction of palatal defects. These defects are either corrected by surgical procedures or prosthetic rehabilitation. Even after surgical correction some patients need prosthesis for speech correction and to prevent nasal regurgitation of food. Few of the patients are entirely dependent on prosthesis rehabilitation alone since, surgical correction is not possible when the defects are large due to excision as in cases of oral cancer, trauma or unrepaired clefts. This study is an attempt to present that the prosthesis alone may not totally correct speech defects and palatography is an inevitable tool for correcting articulatory defects thereby improving speech. It was observed that the prosthesis alone can correct speech defects, yet the clarity of certain vowels and volume of mouth was found to be defective since with the help of palatography and modification of the existing prosthesis the exact articulation of these sounds can be corrected. MATERIALS AND METHODS: 1. Percentage of consonants correct for 20 words (regional language) was used to assess the intelligibility at three clinical Intervals (Before correction of the defect , after correction of the defect with prosthesis and after modifying the prosthesis using palatography). 2. Nasometer (Dr Speech) was used to assess the nasalance for three vowels |a|, |i| and |u| at three clinical intervals (Before correction of the defect , after correction of the defect with prosthesis and after modifying the prosthesis using palatography). 3. Formant evaluation (f0-f5) for three vowels |a|, |i| and |u| was done using PRAAT software at three clinical visits (Before correction of the defect , after correction of the defect with prosthesis and after modifying the prosthesis using palatography). RESULTS: Modified prosthesis using palatography was found to be significantly superior in terms of intelligibility, nasality and formant evaluation showing a higher significance for all the three methods namely Percentage of consonants correct, Nasometer and PRAAT software. CONCLUSION: As per the results obtained, in patients with cleft palate, it was clearly evident that palatal obturators modified by palatography showed a significance of P< 0.001 in terms of nasality and intelligibility. In spectrographic evaluation using PRAAT software the significance level was found to be P<0.05 for all the three vowels using a modified obturator prosthesis

Models and analysis of vocal emissions for biomedical applications

This book of Proceedings collects the papers presented at the 3rd International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2003, held 10-12 December 2003, Firenze, Italy. The workshop is organised every two years, and aims to stimulate contacts between specialists active in research and industrial developments, in the area of voice analysis for biomedical applications. The scope of the Workshop includes all aspects of voice modelling and analysis, ranging from fundamental research to all kinds of biomedical applications and related established and advanced technologies

Vocal rehabilitation after total laryngectomy.

Vocal rehabilitation after total laryngectomy

Revisión de las Tecnologías y Aplicaciones del Habla Sub-vocal

This paper presents a review of the main applicative and methodological approaches that have been developed in recent years for sub-vocal speech or silent language. The sub-vocal speech can be defined as the identification and characterization of bioelectric signals that control the vocal tract, when is not produced sound production by the caller. The first section makes a deep review of methods for detecting silent language. In the second part are evaluated the technologies implemented in recent years, followed by a review of the main applications of this type of speech and finally present a broad comparison between jobs that have been developed in industry and academic applications.Este trabajo presenta una revisión de estado de las principales temáticas aplicativas y metodológicas del habla sub-vocal que se han venido desarrollando en los últimos años. La primera sección hace una honda revisión de los métodos de detección del lenguaje silencioso. En la segunda parte se evalúan las tecnologías implementadas en los últimos años, seguido de un análisis en las principales aplicaciones de este tipo de lenguaje y finalmente presentado una amplia comparación entre los trabajos que se han hecho en industria y academia utilizando este tipo de desarrollos

An Invivo study to Compare the Difference in Speech Sounds Observed with Conventional and Customized Palatal Contour Dentures: A Hospital Based study

INTRODUCTION: Speech has always been the most significant medium for the transmission of ideas and throughout the centuries. It has been one of the main forces for the human progress. Speech is a critical activity of the stomatognathic system, which utilizes the oral cavity as an instrument. A significant part of speech articulation happens inside the oral cavity and any modification of the structures in that will unfavorably influence speech proportionate to the area and magnitude of change. Inability to form the palatal contours to suit ordinary tongue contact as a rule brings about poor speech. Speech is essential to human activity. Therefore phonetics must be considered with mechanics and esthetics as the cardinal factors contributing to the success of the dental prosthesis. AIM OF THE STUDY: The purpose of the study was to compare different speech sounds at different syllable positions in conventional denture and palatal rugae incorporated denture immediately after denture insertion. MATERIALS AND METHODOLOGY: A total of 30 subjects (24 completely edentulous and 6 dentulous) 45-55 years of age were selected for this study. These subjects further divided into 3 groups, Control group: 6 subjects, with natural complete dentition. Study group: 24 subjects, who were completely edentulous. The study was a cross over study in which each individuals had given two sets of denture which was grouped as denture 1: conventional denture and denture 2 : complete dentures with rugae incorporated on maxillary dentures. Tamil Articulation Test [(USHA.D (1986)] was regulated to each subject and recorded. A total of 6 Linguo-palatal phonemes in Tamil |s|, |t|, |d|, |n|, |l| and |dz| were selected for the study. RESULTS: Result shows significance in p value for initial s, middle s, initial t , middle t, initial d, middle n, initial l, initial j and middle j which means there is significant difference in two dentures for these sounds. Whereas the values for middle d, initial n, middle l are not statistically significant. The significance is greater for middle s , initial t and middle j for conventional dentures and initial s, middle t, initial d, middle n, initial l, initial for ruage incorporated dentures. CONCLUSION: It is suggested to duplicate the palatal rugae in complete denture in light of the fact that the articulation of linguo palatal sounds of complete denture with rugae replication was better than the conventional complete denture without rugae replicatio

Voice Prosthesis Use in the First Two Years of Recovery Status Post Total Laryngectomy

Advanced laryngeal cancer requires laryngeal amputation (laryngectomy) (Graham, 1997). As a sequelae to laryngectomy, the surgeon redirects the trachea to the external neck, creating a tracheostoma. This serves as the path for respiration as there is no longer a connection between the trachea and the upper airway (Plante & Beeson, 1999). The laryngectomy deprives the patient of the power source (exhaled air) for speech and the vibrating source (vocal folds) for speech. There are three forms of voice restoration following total laryngectomy: esophageal speech, speech with an artificial larynx, and tracheoesophageal (TE) speech, requiring use of a voice prosthesis (v.p.). TE speech is the focus of the present study. Voice prostheses have evolved immensely since their introduction in1980; therefore, clinicians face a multitude of decisions in managing speech rehabilitation. Questions arise regarding which v.p. design is “best” and what criteria should be considered when selecting v.p.s. This study is a chart review of 11 patients with total laryngectomy and primary TEP who have been in recovery for two years (time frame, 2003-2005). The goal was to identify changes in selected v.p.s and reasons for such changes in the first and second years post-surgery. The primary trend was that patients required progressively shorter v.p.s in the first year vs. negligible change in the second year. A second trend was that clinician-inserted v.p.s tended toward a relatively short useful life. A third trend was that more female laryngectomees were retained in the second year of recovery than males. A fourth trend was the pervasive presence of candida colonization of v.p.s (a condition producing breakdown of the v.p. valve