Cleft palate patients tend to nasalize non nasal phonemes. In order to evaluate their nasality, 5 Japanese vowels pronounced by 7 cleft lip and palate patients are investigated utilizing two spectrum analysis methods. The one is linear prediction analysis, and the other is homomorphic analysis. From the spectrum analysis of the vowel/i/, a distinct peak of spectral envelope is found invariably in the frequency range between the first formant and the second one, which will be refered to as "nasality component". Three parameters (Rn, Ln, Pn) are calculated from this component for the purpose of evaluating the nasality quantitatively. Values of the three parameters decrease or vanish when the speech aid is attached on the palate, and the two parameters (Rn and Pn) have high positive correlation with the perceived nasality level which is estimated by the hearing test. From above results, it is concluded that the "nasality components" extracted by the two spectrum analysis methods will provide a sound basis for clinical appraisal of the nasality in cleft palate speech.
In this paper, a novel imaging system for ultrasonic wave field distribution is described. In our system, a continuous high frequency low intensity probing wave is applied from perpendicular direction to the observing wave so that the phase of the probing wave is modulated instantly by the product of the nonlinear parameter B/A of object and the pressure of observing wave. Then resulting spatially odulated proving wave is detected and demodulated to derive the distribution of the amplitude of the field of the observing wave along the probing beam. The processes are repeated by shifting the position of the probing beam and 2-D image is obtain. This system can be used to get images of ultrasonic field in opaque media such as organs of human body in real time. Several images of ultrasonic field are obtained. Experimental results show the usefulness of this method.
As is well-known, in the practical evaluation and control of the environmental noise and vibration, the principle on an additivity property for energy is widely applied not only to the deterministic signal but also to the stochastic signal. Originally, this principle is effective only in the averaged form of signal fluctuation, and so it is essentially impossible to explain sufficiently every sides of the variety and complexity of actual random phenomena only by use of this fundamental principle. Accordingly, it is fundamentally necessary to find out in a generalized form of the above principle some new type of an additivity rule applicable not only to the first order statistic (i. e. , mean value) but also to the higher order statistical information for various types of actual fluctuation form. In this paper, a new trial toward the statistical prediction for the total probability distribution form of a combined vibration or noise level fluctuations emitted from two different sources is hierarchically proposed from a generalized viewpoint based on the additivity property of arbitrary order cumulant statistics. More concretely, though the probability distribution of combined vibration or noise level fluctuations can be theoretically predicted in two statistical expansion expression form of Hermite and Laguerre series types, its expansion coefficients and statistical properties can be systematically derived in the recursive algorithm styles by use of the proposed general additive principle. Finally, after once the legitimacy of the present theory is confirmed by means of digital simulation technique, the effectiveness of this prediction method is experimentally confirmed too by applying it to the actual data of vibration and noise level fluctuations observed in a large city.
In this paper a new method for the measurement of the change of temperature distribution by using the temperature dependency of the degree of the nonlinear interaction of ultrasonic waves in a medium is proposed. The nonlinear parameter tomography system proposed in the previous paper is used for the purpose. The change of 2-D distribution of temperature is observed non-invasively in real-time as a function of the parameter N=(B/A)/(2p_0c_0^3), where B/A is the nonlinear parameter, p_0 is density and c_0 is sound velocity. Experimental results show the usefulness of this method as a new means of measurement of distribution of temperature in connection with hyperthermia.
A previous analysis of high-frequency acoustical pressure fields on a surface excited by a line source on a semicylindrical concave rigid wall is extended to a three-demensional case for a point source excitation. 1) Acoustical ray and integral form interference field representation, 2) acoustical ray and Whispering Gallery mode representation, and 3) near field perturbation representation are explored. The physical interpretation and the error criterion of these alternative field representations are discussed with numerical evaluations. Furthermore, field representations in the multiplications form of acoustical pressure fields on a plane rigid wall and the function taking into account of effects due to the concave surface with a constant radius of curvature are discribed. As for the two-dimensional case, a combination of rays and Whispering Gallery modes provides a physically appealing method for calculating the acoustical fields.
This paper describes the mechanism of sonic drying on the basis of the experimental results in the standing wave field during the constant rate period. It has been evident at present that the effect of sonic drying is related to the magnitude of the particle velocity, and appears obviously in case the particle velocity is above about 150cm/s. From the experimental results, it has become clear that the constant drying rate in sonic increases proportionally to the approximate square of the particle velocity, regardless of the magnitude of atmospheric pressure, sound frequency and air flow rate, and besides, under the condition of the constant particle velocity, the constant drying rate increases in proportion to the magnitude of atmospheric pressure. From the results above mentioned, it can be said that the increase of constant drying rate is related to the kinetic energy in sonic. It is possible to consider that this energy generates the frictional heat between the air with the particle velocity and the water surface of sample, and raises the temperature of the water surface, its saturated vapor pressure rises, therefore the constant drying rate increases.