Maciej Klaczynski

A vibroacoustic model of selected human larynx diseases.

With the present development of digital registration and methods for processing speech it is possible to make effective objective acoustic diagnostics for medical purposes. These methods are useful as all pathologies and diseases of the human vocal tract influence the quality of a patient’s speech signal. Diagnostics of the voice organ can be defined as an unambiguous recognition of the current condition of a specific voice source. Such recognition is based on an evaluation of essential acoustic parameters of the speech signal. This requires creating a vibroacoustic model of selected deformations of Polish speech in relation to specific human larynx diseases. An analysis of speech and parameter mapping in 29-dimensional space is reviewed in this study. Speech parameters were extracted in time, frequency and cepstral (quefrency) domains resulting in diagrams that qualified symptoms and conditions of selected human larynx diseases. The paper presents graphically selected human larynx diseases.

Computer-assisted HFCC-based learning system for people with speech sound disorders

To be efficacious, treatment of articulation dysfunctions must be personalized to the patients needs. A crucial phase in the treatment process belongs to repetitions drills of target sounds. To improve the outcomes we developed a software program to support articulation treatment. The main advantage of this application is in self-evaluation of correctness of the practiced sound in the absence of treating speech-language pathologist facilitating frequent repetitions. To make this application successful we applied to the speech signals Human Factor Cepstral Coefficients (HFCC), which are a modification of Mel Frequency Cepstral Coefficients (MFCC). To measure similarity between the acoustic target signal patterns and acoustic test (patient response) signal, the Dynamic Time Warping (DTW) algorithm was used. The application was created by means of LabVIEW development environment that enables to rehearse selected 20 Polish words with phonemes to be practiced located in the word initial positions.

Accuracy of Assessing the Level of Impulse Sound From Distant Sources

Impulse sound events are characterised by ultra high pressures and low frequencies. Lower frequency sounds are generally less attenuated over a given distance in the atmosphere than higher frequencies. Thus, impulse sounds can be heard over greater distances and will be more affected by the environment. To calculate a longterm average immission level it is necessary to apply weighting factors like the probability of the occurrence of each weather condition during the relevant time period. This means that when measuring impulse noise at a long distance it is necessary to follow environmental parameters in many points along the way sound travels and also to have a database of sound transfer functions in the long term. The paper analyses the uncertainty of immission measurement results of impulse sound from cladding and destroying explosive materials. The influence of environmental conditions on the way sound travels is the focus of this paper.