This paper presents a new modulation method for an ultrasonic Doppler flow meter with high range resolution. In this method, transmitted and received waves are modulated and demodulated respectively depending upon the specified new sequences. The cross-correlation values are zero except for peak value. Is sought a pairof new sequences with such cross-correlation property which provides high sensitivity for detection. The advantages of the proposed method are that it employes continuous waves and enables complete elimination of unfavorable reflected waves. Therefore, the present method is superior to a pulsed Doppler method and an M-sequence modulation method owing to higher detection sensitivity.
The Priciple, the construction, the performance, and the characteristics of three kinds of visual speech trainers are summarized, which were developed for hard of hearing children. Those trainers, that is a 2-dimensional pitch-intensity indicator, an articulatory trainer of vowels and an intonation indicator, have CRT with a large screen(11''), and speech parameters are indicated as information of position on the screen. As the internal condition of the devices is automatically controlled to fit input speech, the speech parameters can accurately be extracted and the trainers can easily be operated. Finally, discussions are made for further development of the trainers reported in this paper, and new systems of speech trainers are proposed. By use of those trainers, speech parameters increase in number which we can transmit at once to hard of hearing children.
Three types of visual speech trainers, i. e. a 2-dimensional pitch-intensity indicator, an articulatory trainer of vowels and an intonation indicator, were systematically used for about a year and ten months in the training of fourteen(or five) hard of hearing children(aged 7 to12). The results of the trainings are summarized as follows: (1)In the trainings scheduled about 10 times(ten minutes per once) by use of the 2-dimensional pitch-intensity indicator, the children mastered control of the larynx relying on the somatic feedback. (2)By conducting the pitch control and articulatory trainings in parallel, children uttered at an unstable pitch temporarily. However, continuation of the trainings for about another 10 times, resulted in the children being able to utter sustained vowels in the correct articulation and at the pertinent pitch. (3)Training of intonation is useful for correcting intonation, but not effective so much for correcting the rhythms. These results can also be verified by listening to the utterances of the children concerned.
One of the representative statistics actually used in the evaluation and regulation problems of the environmental noise and vibration is the so-called L_α(α=5, 10, 50, …) evaluationlevel, which is directly related to the probability distribution form. This fact makes it difficult to solve the estimation and prediction problems of the L_α level systematically in the actual engineering field of noise and viblation control. First, our main interest is devoted to solve the estimation problem in the form of non-sequential algorithm for L_αlevel. By introducing a generalized non-stationary model for the internal structure of random noise and vibration, a unified cumulative distribution function of the observed non-stationary random fluctuation is proposed in advance in the form of orthogonal and/or non-orthogonal expansion series type expression. The important evaluation index, L_α level, is directly calculated by use of the generalized expansion theorem derived from the above unified distribution function in the form of non-sequential algorithm. Next, we investigate a theoretical estimation procedure based on the stochastic approximation method in the form of sequential algorithm. Furthermore, we have experimentally confirmed the validity and effectiveness of the above two different estimation methods not only by means of digital simulation but also by experimentally observed road traffic noise data in Hiroshima City. All of the experimental results clearly show the good agreement with the present theory.
We carried out a questionnaire survey on community noise to 790 residents in various dwellings from the Hokkaido to Kyusyu districts. Community noise was found to be the most annoying next to road traffic noise. About half of the respondents suffered from it and one-third were anxious for their disturbing others. Almost all instruments in our surroundings were listed as noise sources. Though the opinion concerning community noise were of good sense as a whole, by the projective technique many respondents were found to be quite selfish. This fact seems to be important as a cause of the community noise problem. As a countermeasure, a good human relation in the neighborhood, a new sound moral, and sound insulation rooms were wanted.