Estimation of the vocal tract area function producing fricative consonants is performed using the spectral matching technique. The model is composed of an equivalent acoustical tube, a radiation impedance and a noise source which is put in the vocal tract. The estimated area functions for /s/, /∫/, /h/ and /f/ are distinctive, and each shows the unique characteristics which correspond to the articulation of the consonant. Thus, it is verified that the proposed method is beneficial in analyzing the features of fricative consonants.

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“Principapl itch” is defined as somewhast teadyp itch perceivedfr om periodically frequencym odulatedto nes, l ikev ibratot ones. Principapl itch of vibratot onesw hose frequencyal onem odulatedp eriodicalliys indicatedto be locateda roundt heir carrier frequencie (st hem iddleo f the extento f FM). Wes tudiedw heret he principal pitch of FM-AM to nesi s locatedb y the psychoacousticeaxlp erimenuts inga methodo f adjustment. FM-AM tones is defineda s vibratot one whosef requencyan d amplitude are periodicallmy odulated by an identicalm odulationw aveformsi multaneously. The principapl itch of FM-AM tones is shiftedh ighert han their carrierf requenciews hen the phased ifferencbee tween FM and AM is in-phase, and lowerw heni t is anti-phase. The shiftedi ntervalf romt he carrierf requenctyo the localizedp rincipal pitch of FM-AM tonei is proportionatlo the extent of FM and the square of the degree of AM. To interpreth esee xperimentrael sults, we suppose the psychoacousticmalo delw hich is the expansion of the pitch averaginmg echanismto perceivep rincipapl itch of FM tones. In this modelc, ontinuousclyh anginpgi tch of FM-AM to nesi s sampledw, eighted with its amplitudfel uctuationr, e gisteredin sensorys tore, and averagede veryc ertain moment. Thew eightinpgr ocessin this modeli s constructewd ithl oudnesps erception mechanism and the mechanismto perceivfel uctuatiosnt rength.We also discussed how the effect of intensity on pitch influences our experimentrael sults.

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In this paper, we describe a procedure for automatically extracting demisyllables (DSs) from Thai isolated source words of the forms consonant-vowel, vowel-consonant, and vowel. Routines that are particular to each category of source words are used to establish DS boundary locations. All segmental cues are derivable from the cepstrum representing a log spectral envelope that approximately passes through peaks of the fine structure, which have been manually determined based on spoken source words of one male talker. The automatic procedure has been used to extract DSs from spoken source words of two new talkers: one male and one female. Manual comparisons have shown that automatically obtained DS boundary locations were within three frames (1 frame is 10ms) from the corresponding locations obtained manually by a trained native linguist. For the male talker, 94.2% of the automatically obtained locations coincided with the corresponding manually obtained locations, and3.5%, 1.9%, and0.4% differed by one, two, and three frames, respectively; for the female talker, 95.7% coincided, and 3.3%, 0.8%, and 0.2% differed by one, two, and three frames, respectively. The above results are comparable with the results of using the automatic procedure to extract the DSs from the source words of the old talker: 97.5% coincided, and2.3% and 0.2% differed by one and two frames, respectively. These results indicate that the automatic procedure promises a very good first estimate set of DSs.

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A new method of localizing a sound image in the frontal half of the horizontal plane (from side to side) of a listener, including control of direction and distance in two channel stereophonic reproduction, is proposed. The method is such that signals with respect to actual and phantom sources created by electronic circuits are controlled by the intensity stereo theory. A control system utilizing four-channel panpot (panorama potentiometer) has been constructed, and the experimental results show that it works quite satisfactorily.

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A simulated in situ measurement system for hearing aids was developed. The system consists of a head and torso simulator (SAMRAI) with a simplified ear simulator and an equipment for digital signal processing (SPIRIT). SAMRAI was constructed on the basis of the average dimensions of Japanese male adults. The ear simulator, newly developed for practical use, is terminated in a simple resistance of 320 cgs acoustic ohms. The measurement result on SAMRAI with the ear simulator shows good agreement with the real ear data. And several measurement results using this system are discussed. Finally we show a method of measuring vent response using an ear simulator, which has a termination impedance not similar to human eardrum impedance.

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The experimentr eportedh ere was designed to find the causef or dissolvingth e urinary stones rapidly in EDTA solution by relatively low power ultrasonic irradiation without direct disintegration of the stone and systemice ffect of heating. In this experiment it has become clear that the irradiation with ultrasonic wave accelerated the dissolution of stones. The quantitative experimental studies using spherically shaped gypsum as model sample, moreover, have revealed that the ultrasonic irradiation increased the cheical dissolution rates of the model stone by10to30times. It may be probable that the increase in dissolution rate is ascribed to the following facts; the effects due to the microstream generated by the vibration of bubble associated with the ultrasonic irradiation and the effects due to the dance of the stone in EDTA solution by an intermittent straight flow generated by the ultrasonic wave pulse.

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