Numerical simulation of transfer and attenuation characteristics of soft-tissue conducted sound originating from vocal tract

A non-audible murmur (NAM), a very weak speech sound produced without vocal cord vibration, can be detected by a special NAM microphone attached to the neck, thereby providing a new speech communication tool for functional speech disorders as well as human-to-machine and human-to-human interfaces with inaudible voice input for use with unimpaired. The NAM microphone is a condenser microphone covered with soft-silicone impression material that provides good impedance matching with the soft tissues of the neck. Because higher-frequency components are suppressed severely, however, the NAM detected with this device can be insufficiently clear. To improve NAM clarity, the mechanism of NAM production as well as the transfer characteristics of the NAM in soft neck tissues must be clarified. We have investigated sound propagation from the vocal tract to the neck surface, using a finite difference time domain method and a head model based on magnetic resonance imaging scans. Numerical results show that, compared to air-conducted sound detected in front of a mouth, soft-tissue-conducted sound attenuates 50 dB at 1 kHz, which consists of 30 dB full-range attenuation due to air-to-soft-tissues transmission loss and -10 dB/octave spectral decay due to a propagation loss in soft tissues. The decay agrees well with the spectral characteristics of the measured NAM. (C) 2008 Elsevier Ltd. All rights reserved.ArticleAPPLIED ACOUSTICS. 70(3):469-472 (2009)journal articl

Audible (Normal) Speech and Inaudible Murmur Recognition Using NAM Microphone

EUSIPCO2004: the 12th European Signal Processing Conference, September 6-10, 2004, Vienna, Austria.In this paper, we present audible (normal) speech and inaudible murmur hidden Markov models based automatic speech recognition using NAM microphone. The NAM (Non-Audible Murmur) microphone is a special device, which can be used for capturing inaudible murmur speech. The device is based on the stethoscope, which is used in medical science. By attaching the NAM microphone behind the talker's ear, we can receive very quietly uttered speech and perform automatic speech recognition in a conventional way. Privacy, robustness to environmental, and a useful tool for sound-impaired people noise belong to the advantages of the NAM microphone. Using adaptation techniques, we created hidden Markov models for inaudible speech and we performed automatic speech recognition. The achieved results are very promising, and prove the effectiveness of NAM microphone In this paper, we also introduce our work for recognizing normal speech using NAM microphone. The idea is to take advantage of noise robustness of NAM microphone. In our experiments, we achieved a 93.82% word accuracy in clean environment, and a 93.08% word accuracy in noisy environment. In this paper, we also introduce two techniques to intergrate inaudible murmur and audible speech recognition using NAM microphone. In both cases, we achieved a 92.01% word accuracy on average, which is a very promising result

EMG-to-Speech: Direct Generation of Speech from Facial Electromyographic Signals

The general objective of this work is the design, implementation, improvement and evaluation of a system that uses surface electromyographic (EMG) signals and directly synthesizes an audible speech output: EMG-to-speech

Advancing Electromyographic Continuous Speech Recognition: Signal Preprocessing and Modeling

Speech is the natural medium of human communication, but audible speech can be overheard by bystanders and excludes speech-disabled people. This work presents a speech recognizer based on surface electromyography, where electric potentials of the facial muscles are captured by surface electrodes, allowing speech to be processed nonacoustically. A system which was state-of-the-art at the beginning of this book is substantially improved in terms of accuracy, flexibility, and robustness

Advancing Electromyographic Continuous Speech Recognition: Signal Preprocessing and Modeling

Speech is the natural medium of human communication, but audible speech can be overheard by bystanders and excludes speech-disabled people. This work presents a speech recognizer based on surface electromyography, where electric potentials of the facial muscles are captured by surface electrodes, allowing speech to be processed nonacoustically. A system which was state-of-the-art at the beginning of this book is substantially improved in terms of accuracy, flexibility, and robustness

Extended frequency amplification, speech recognition and functional performance in children with mild to severe sensorineural hearing loss

A substantial body of research points to the benefits of fitting hearing instruments that provides extended high frequency amplification. Most published research were done on adults or in controlled laboratory settings. It is therefore necessary for peadiatric audiologists to critically assess the effects that this extended high frequency amplification has on the individual child fitted with hearing instruments. A quantitative research method was selected to explore the possible correlations between extended high frequency amplification and the influence this extended high frequency amplification has on speech recognition and functional performance in children with mild to severe sensory neural hearing loss. A quasiexperimental design was selected. This design accommodated a one-group (single-system) pre-test versus post-test design. Baseline assessments were done and all participants were subjected to pre- and post-intervention assessments. Six participants were fitted with hearing instruments which provided extended high frequency amplification. A baseline assessment was done with current hearing instruments after which participants were assessed with the hearing instruments with extended high frequency amplification. Aided audiological assessments were done without the extended high frequencies after which participants were evaluated with the added high frequencies. Speech recognition testing and functional performance questionnaires were used to compare the outcomes obtained with and without the extended high frequency amplification. A t-test was used for hypothesis testing to determine if extended range amplification increased speech recognition abilities and functional performance, and if these increases were statistically significant. Results were varied where some participants performed better and some performed worse with the added extended range amplification during speech recognition testing and functional performances observed at home. These varied results were statistically insignificant. However, statistically significant evidence was obtained to indicate that extended high frequency amplification increased the functional performance observed at school. The study concluded that the paediatric audiologist should know the effect fitting hearing instruments capable of extended high frequency amplification have on speech recognition abilities and functional performances. Fitting hearing instruments with extended high frequency amplification should however be done with caution because not all children benefited from extended bandwidth amplification. This underlines the importance of following a strict evidence-based approach that incorporates objective and subjective assessment approaches. This will provide the paediatric audiologist with real world evidence of the success of the amplification strategy that is followed.Dissertation (MCommunication Pathology)--University of Pretoria, 2012.Speech-Language Pathology and AudiologyUnrestricte

A sound takes place : noise, difference and sonorous individuation after Deleuze

This thesis traces an idea of auditory influence or sonorous individuation through three distinct areas of sound-art practice. These three areas are discussed according to a kind of spatial contraction, passing from the idea of auditory influence in acoustic ecology and field recording practices, to its expression in work happening at the intersection of soundart and architecture, and finally towards headphonic space and the interior of the body. Through these diverse fields and divergent practices a common idea pertaining to the influence of the auditory upon listening subjects is revealed, which itself brings up questions concerning the constitution of a specifically auditory subjectivity in relation to the subject ‘as a whole’. Towards the expression of a theory of sonorous individuation appropriate to practices approaching sonorous matters in the mode of a sonic materialism, the philosophical work of Gilles Deleuze is called upon as a critical framework. This philosophical framework is adopted as it clearly expresses a spatio-temporally contingent theory of individuation. This particular contingency becomes necessary in exploring works wherein the production of acoustic space is understood as being indissociable from a subjective ‘modulation’ or process of sonorous individuation, in which auditory individuals or listening subjects are bound within and influenced by acoustic spaces in which a sound takes place and a self takes shape.EThOS - Electronic Theses Online ServiceGBUnited Kingdo